From nobody Fri Jun 12 22:47:19 2026 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 319FB27B4F7; Tue, 12 May 2026 02:03:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=13.77.154.182 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778551397; cv=none; b=Lm+E2J7Qcaj9lSLOc5pyWyiHr5H5SKnYPNeQ9NIOArIPJW7MEAPWgChu11AQqEYw5VHC+McQD8axtgpGONz6UTZHLlacG93cIw13EcRVh2GeaKJCkFEBqpQLuuVDOT27qbNlwBBlaSedw3FIXrAJE1E1cLkqeYOV9bEmEnuRr60= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778551397; c=relaxed/simple; bh=iNCq/6LJynBsDvVqOUXofG0jeHT8WBHDLN51gLy0Qh8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=j/yWQlgEAr+z5/EOppx0dKSoulk6Fz3JornBW4CF5zwPOHQarvCzqN89UY4BSCDsIPnG/CMcP8qG4rf9WYtTqkhKFW4iHBNQiiRZ4ttRo41sGonOCyYjsaDjaLp0goZLMwJs4DHirh9E9oG3DxAYm02RX0HnmdLIaOWrbg/ECMk= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com; spf=pass smtp.mailfrom=linux.microsoft.com; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b=iGfqlpnf; arc=none smtp.client-ip=13.77.154.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="iGfqlpnf" Received: from mrdev.corp.microsoft.com (unknown [13.88.17.9]) by linux.microsoft.com (Postfix) with ESMTPSA id 595CF20B7167; Mon, 11 May 2026 19:03:12 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 595CF20B7167 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1778551393; bh=ynRA88Z5bV4VTptbAf0c2VvjcKoPPD/m6Qh24ri9A0Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=iGfqlpnfckGmAxldX20yDjRJXavwUzHI1zm/PySdMYbM1tet6noDkmIZc77Wl0Owf XgIanbmPyUTDJBzpOkNyvEbadVA9iQ5ADMAoGGUcEs7YdW6JMWXikOpeBOIBxAHAST rG3xzpjKfGxNdIbdehK3FPa92G3X+L7JUFiUoL9w= From: Mukesh R To: hpa@zytor.com, robin.murphy@arm.com, robh@kernel.org, wei.liu@kernel.org, mrathor@linux.microsoft.com, mhklinux@outlook.com, muislam@microsoft.com, namjain@linux.microsoft.com, magnuskulke@linux.microsoft.com, anbelski@linux.microsoft.com, linux-kernel@vger.kernel.org, linux-hyperv@vger.kernel.org, iommu@lists.linux.dev, linux-pci@vger.kernel.org, linux-arch@vger.kernel.org Cc: kys@microsoft.com, haiyangz@microsoft.com, decui@microsoft.com, longli@microsoft.com, tglx@kernel.org, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, joro@8bytes.org, will@kernel.org, lpieralisi@kernel.org, kwilczynski@kernel.org, bhelgaas@google.com, arnd@arndb.de, jacob.pan@linux.microsoft.com Subject: [PATCH V3 01/11] iommu/hyperv: Rename hyperv-iommu.c to hyperv-irq.c Date: Mon, 11 May 2026 19:02:49 -0700 Message-ID: <20260512020259.1678627-2-mrathor@linux.microsoft.com> X-Mailer: git-send-email 2.51.2.vfs.0.1 In-Reply-To: <20260512020259.1678627-1-mrathor@linux.microsoft.com> References: <20260512020259.1678627-1-mrathor@linux.microsoft.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" This file actually implements irq remapping, so rename to more appropriate hyperv-irq.c. A new file to implement hyperv iommu will be introduced later. Also, it should not be tied to HYPERV_IOMMU, but to CONFIG_HYPERV and IRQ_REMAP. The file already has #ifdef CONFIG_IRQ_REMAP. Reviewed-by: Anirudh Rayabharam (Microsoft) Signed-off-by: Mukesh R Reviewed-by: Souradeep Chakrabarti --- MAINTAINERS | 2 +- drivers/iommu/Makefile | 2 +- drivers/iommu/{hyperv-iommu.c =3D> hyperv-irq.c} | 6 +++--- drivers/iommu/irq_remapping.c | 2 +- 4 files changed, 6 insertions(+), 6 deletions(-) rename drivers/iommu/{hyperv-iommu.c =3D> hyperv-irq.c} (99%) diff --git a/MAINTAINERS b/MAINTAINERS index d1cc0e12fe1f..f803a6a38fee 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -11914,7 +11914,7 @@ F: drivers/clocksource/hyperv_timer.c F: drivers/hid/hid-hyperv.c F: drivers/hv/ F: drivers/input/serio/hyperv-keyboard.c -F: drivers/iommu/hyperv-iommu.c +F: drivers/iommu/hyperv-irq.c F: drivers/net/ethernet/microsoft/ F: drivers/net/hyperv/ F: drivers/pci/controller/pci-hyperv-intf.c diff --git a/drivers/iommu/Makefile b/drivers/iommu/Makefile index 0275821f4ef9..335ea77cced6 100644 --- a/drivers/iommu/Makefile +++ b/drivers/iommu/Makefile @@ -30,7 +30,7 @@ obj-$(CONFIG_TEGRA_IOMMU_SMMU) +=3D tegra-smmu.o obj-$(CONFIG_EXYNOS_IOMMU) +=3D exynos-iommu.o obj-$(CONFIG_FSL_PAMU) +=3D fsl_pamu.o fsl_pamu_domain.o obj-$(CONFIG_S390_IOMMU) +=3D s390-iommu.o -obj-$(CONFIG_HYPERV_IOMMU) +=3D hyperv-iommu.o +obj-$(CONFIG_HYPERV) +=3D hyperv-irq.o obj-$(CONFIG_VIRTIO_IOMMU) +=3D virtio-iommu.o obj-$(CONFIG_IOMMU_SVA) +=3D iommu-sva.o obj-$(CONFIG_IOMMU_IOPF) +=3D io-pgfault.o diff --git a/drivers/iommu/hyperv-iommu.c b/drivers/iommu/hyperv-irq.c similarity index 99% rename from drivers/iommu/hyperv-iommu.c rename to drivers/iommu/hyperv-irq.c index 479103261ae6..d11076f906fb 100644 --- a/drivers/iommu/hyperv-iommu.c +++ b/drivers/iommu/hyperv-irq.c @@ -8,6 +8,8 @@ * Author : Lan Tianyu */ =20 +#ifdef CONFIG_IRQ_REMAP + #include #include #include @@ -24,8 +26,6 @@ =20 #include "irq_remapping.h" =20 -#ifdef CONFIG_IRQ_REMAP - /* * According 82093AA IO-APIC spec , IO APIC has a 24-entry Interrupt * Redirection Table. Hyper-V exposes one single IO-APIC and so define @@ -331,4 +331,4 @@ static const struct irq_domain_ops hyperv_root_ir_domai= n_ops =3D { .free =3D hyperv_root_irq_remapping_free, }; =20 -#endif +#endif /* CONFIG_IRQ_REMAP */ diff --git a/drivers/iommu/irq_remapping.c b/drivers/iommu/irq_remapping.c index c2443659812a..41bf65e4ea88 100644 --- a/drivers/iommu/irq_remapping.c +++ b/drivers/iommu/irq_remapping.c @@ -108,7 +108,7 @@ int __init irq_remapping_prepare(void) else if (IS_ENABLED(CONFIG_AMD_IOMMU) && amd_iommu_irq_ops.prepare() =3D=3D 0) remap_ops =3D &amd_iommu_irq_ops; - else if (IS_ENABLED(CONFIG_HYPERV_IOMMU) && + else if (IS_ENABLED(CONFIG_HYPERV) && hyperv_irq_remap_ops.prepare() =3D=3D 0) remap_ops =3D &hyperv_irq_remap_ops; else --=20 2.51.2.vfs.0.1 From nobody Fri Jun 12 22:47:19 2026 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 5253B2DF6F6; Tue, 12 May 2026 02:03:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=13.77.154.182 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778551401; cv=none; b=sqP4dcQFIZCALSF8dRsHTiocwvw/6H2GD496KtW9ssZ/AEhsuJFsscO14JkWT/JNWIu0f3Fcy6GWFWT0Z5GsbcD4ebOLL239QY8VAViVFT0A/a+bMpKAF3BGdcBK7nwdGS94OX1wbDDmrboWUjWHK+9DzGuekJqUjOAwOcwl+bA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778551401; c=relaxed/simple; bh=LcfG3IrvAZWVpsoUtEdkAhTVPBkDUMBil1NiTMydS6E=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=P7jC70nWJWRtad5ceYA16cnXH3DC1H3EOA/p2nd6eGkKuiZ03hNAqWeiSMjNKjBCsPR+n0m60n5nGcojkc/l+i2E2oTJh0Erb/i7RPO/kuM0Tq9HhWns0y+Nx6e27IiauPujZgIZtMzzaoPLHAhl1xbRw5rvvL+t/ahOOy2dAi8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com; spf=pass smtp.mailfrom=linux.microsoft.com; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b=OR3emYC8; arc=none smtp.client-ip=13.77.154.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="OR3emYC8" Received: from mrdev.corp.microsoft.com (unknown [13.88.17.9]) by linux.microsoft.com (Postfix) with ESMTPSA id 3625420B7168; Mon, 11 May 2026 19:03:14 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 3625420B7168 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1778551395; bh=iE0K4VJu6prawC3f3j3mDOXzwZlAvYKEOpptNq4J108=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OR3emYC8ek4xtV1M4PEb7qDwYWAT4E9cBROwB7CpylEIm42Q7JeTCv9P8YSIzhywB 25REQqf/9QEkrleokFbaG8sW0J/40VYTfVB/7/QeRXDV0QAEJ5buWhmcpdtir9672g 4k5BdJrouaylSnb/TBa+XJ3YSKp6inv5K4fzxYLc= From: Mukesh R To: hpa@zytor.com, robin.murphy@arm.com, robh@kernel.org, wei.liu@kernel.org, mrathor@linux.microsoft.com, mhklinux@outlook.com, muislam@microsoft.com, namjain@linux.microsoft.com, magnuskulke@linux.microsoft.com, anbelski@linux.microsoft.com, linux-kernel@vger.kernel.org, linux-hyperv@vger.kernel.org, iommu@lists.linux.dev, linux-pci@vger.kernel.org, linux-arch@vger.kernel.org Cc: kys@microsoft.com, haiyangz@microsoft.com, decui@microsoft.com, longli@microsoft.com, tglx@kernel.org, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, joro@8bytes.org, will@kernel.org, lpieralisi@kernel.org, kwilczynski@kernel.org, bhelgaas@google.com, arnd@arndb.de, jacob.pan@linux.microsoft.com Subject: [PATCH V3 02/11] x86/hyperv: Cosmetic changes in irqdomain.c for readability Date: Mon, 11 May 2026 19:02:50 -0700 Message-ID: <20260512020259.1678627-3-mrathor@linux.microsoft.com> X-Mailer: git-send-email 2.51.2.vfs.0.1 In-Reply-To: <20260512020259.1678627-1-mrathor@linux.microsoft.com> References: <20260512020259.1678627-1-mrathor@linux.microsoft.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Make cosmetic changes: o Rename struct pci_dev *dev to *pdev since there are cases of struct device *dev in the file and all over the kernel o Rename hv_build_pci_dev_id to hv_build_devid_type_pci in anticipation of building different types of device IDs o Fix checkpatch.pl issues with return and extraneous printk o Replace spaces with tabs o Rename struct hv_devid *xxx to struct hv_devid *hv_devid given code paths involve many types of device IDs o Fix indentation in a large if block by using goto. There are no functional changes. Reviewed-by: Anirudh Rayabharam (Microsoft) Signed-off-by: Mukesh R Reviewed-by: Souradeep Chakrabarti --- arch/x86/hyperv/irqdomain.c | 198 +++++++++++++++++++----------------- 1 file changed, 104 insertions(+), 94 deletions(-) diff --git a/arch/x86/hyperv/irqdomain.c b/arch/x86/hyperv/irqdomain.c index 365e364268d9..b3ad50a874dc 100644 --- a/arch/x86/hyperv/irqdomain.c +++ b/arch/x86/hyperv/irqdomain.c @@ -1,5 +1,4 @@ // SPDX-License-Identifier: GPL-2.0 - /* * Irqdomain for Linux to run as the root partition on Microsoft Hyperviso= r. * @@ -14,8 +13,8 @@ #include #include =20 -static int hv_map_interrupt(union hv_device_id device_id, bool level, - int cpu, int vector, struct hv_interrupt_entry *entry) +static int hv_map_interrupt(union hv_device_id hv_devid, bool level, + int cpu, int vector, struct hv_interrupt_entry *ret_entry) { struct hv_input_map_device_interrupt *input; struct hv_output_map_device_interrupt *output; @@ -32,7 +31,7 @@ static int hv_map_interrupt(union hv_device_id device_id,= bool level, intr_desc =3D &input->interrupt_descriptor; memset(input, 0, sizeof(*input)); input->partition_id =3D hv_current_partition_id; - input->device_id =3D device_id.as_uint64; + input->device_id =3D hv_devid.as_uint64; intr_desc->interrupt_type =3D HV_X64_INTERRUPT_TYPE_FIXED; intr_desc->vector_count =3D 1; intr_desc->target.vector =3D vector; @@ -44,7 +43,7 @@ static int hv_map_interrupt(union hv_device_id device_id,= bool level, =20 intr_desc->target.vp_set.valid_bank_mask =3D 0; intr_desc->target.vp_set.format =3D HV_GENERIC_SET_SPARSE_4K; - nr_bank =3D cpumask_to_vpset(&(intr_desc->target.vp_set), cpumask_of(cpu)= ); + nr_bank =3D cpumask_to_vpset(&intr_desc->target.vp_set, cpumask_of(cpu)); if (nr_bank < 0) { local_irq_restore(flags); pr_err("%s: unable to generate VP set\n", __func__); @@ -61,7 +60,7 @@ static int hv_map_interrupt(union hv_device_id device_id,= bool level, =20 status =3D hv_do_rep_hypercall(HVCALL_MAP_DEVICE_INTERRUPT, 0, var_size, input, output); - *entry =3D output->interrupt_entry; + *ret_entry =3D output->interrupt_entry; =20 local_irq_restore(flags); =20 @@ -71,21 +70,19 @@ static int hv_map_interrupt(union hv_device_id device_i= d, bool level, return hv_result_to_errno(status); } =20 -static int hv_unmap_interrupt(u64 id, struct hv_interrupt_entry *old_entry) +static int hv_unmap_interrupt(u64 id, struct hv_interrupt_entry *irq_entry) { unsigned long flags; struct hv_input_unmap_device_interrupt *input; - struct hv_interrupt_entry *intr_entry; u64 status; =20 local_irq_save(flags); input =3D *this_cpu_ptr(hyperv_pcpu_input_arg); =20 memset(input, 0, sizeof(*input)); - intr_entry =3D &input->interrupt_entry; input->partition_id =3D hv_current_partition_id; input->device_id =3D id; - *intr_entry =3D *old_entry; + input->interrupt_entry =3D *irq_entry; =20 status =3D hv_do_hypercall(HVCALL_UNMAP_DEVICE_INTERRUPT, input, NULL); local_irq_restore(flags); @@ -115,67 +112,71 @@ static int get_rid_cb(struct pci_dev *pdev, u16 alias= , void *data) return 0; } =20 -static union hv_device_id hv_build_pci_dev_id(struct pci_dev *dev) +static union hv_device_id hv_build_devid_type_pci(struct pci_dev *pdev) { - union hv_device_id dev_id; + int pos; + union hv_device_id hv_devid; struct rid_data data =3D { .bridge =3D NULL, - .rid =3D PCI_DEVID(dev->bus->number, dev->devfn) + .rid =3D PCI_DEVID(pdev->bus->number, pdev->devfn) }; =20 - pci_for_each_dma_alias(dev, get_rid_cb, &data); + pci_for_each_dma_alias(pdev, get_rid_cb, &data); =20 - dev_id.as_uint64 =3D 0; - dev_id.device_type =3D HV_DEVICE_TYPE_PCI; - dev_id.pci.segment =3D pci_domain_nr(dev->bus); + hv_devid.as_uint64 =3D 0; + hv_devid.device_type =3D HV_DEVICE_TYPE_PCI; + hv_devid.pci.segment =3D pci_domain_nr(pdev->bus); =20 - dev_id.pci.bdf.bus =3D PCI_BUS_NUM(data.rid); - dev_id.pci.bdf.device =3D PCI_SLOT(data.rid); - dev_id.pci.bdf.function =3D PCI_FUNC(data.rid); - dev_id.pci.source_shadow =3D HV_SOURCE_SHADOW_NONE; + hv_devid.pci.bdf.bus =3D PCI_BUS_NUM(data.rid); + hv_devid.pci.bdf.device =3D PCI_SLOT(data.rid); + hv_devid.pci.bdf.function =3D PCI_FUNC(data.rid); + hv_devid.pci.source_shadow =3D HV_SOURCE_SHADOW_NONE; =20 - if (data.bridge) { - int pos; + if (data.bridge =3D=3D NULL) + goto out; =20 - /* - * Microsoft Hypervisor requires a bus range when the bridge is - * running in PCI-X mode. - * - * To distinguish conventional vs PCI-X bridge, we can check - * the bridge's PCI-X Secondary Status Register, Secondary Bus - * Mode and Frequency bits. See PCI Express to PCI/PCI-X Bridge - * Specification Revision 1.0 5.2.2.1.3. - * - * Value zero means it is in conventional mode, otherwise it is - * in PCI-X mode. - */ + /* + * Microsoft Hypervisor requires a bus range when the bridge is + * running in PCI-X mode. + * + * To distinguish conventional vs PCI-X bridge, we can check + * the bridge's PCI-X Secondary Status Register, Secondary Bus + * Mode and Frequency bits. See PCI Express to PCI/PCI-X Bridge + * Specification Revision 1.0 5.2.2.1.3. + * + * Value zero means it is in conventional mode, otherwise it is + * in PCI-X mode. + */ =20 - pos =3D pci_find_capability(data.bridge, PCI_CAP_ID_PCIX); - if (pos) { - u16 status; + pos =3D pci_find_capability(data.bridge, PCI_CAP_ID_PCIX); + if (pos) { + u16 status; =20 - pci_read_config_word(data.bridge, pos + - PCI_X_BRIDGE_SSTATUS, &status); + pci_read_config_word(data.bridge, pos + PCI_X_BRIDGE_SSTATUS, + &status); =20 - if (status & PCI_X_SSTATUS_FREQ) { - /* Non-zero, PCI-X mode */ - u8 sec_bus, sub_bus; + if (status & PCI_X_SSTATUS_FREQ) { + /* Non-zero, PCI-X mode */ + u8 sec_bus, sub_bus; =20 - dev_id.pci.source_shadow =3D HV_SOURCE_SHADOW_BRIDGE_BUS_RANGE; + hv_devid.pci.source_shadow =3D + HV_SOURCE_SHADOW_BRIDGE_BUS_RANGE; =20 - pci_read_config_byte(data.bridge, PCI_SECONDARY_BUS, &sec_bus); - dev_id.pci.shadow_bus_range.secondary_bus =3D sec_bus; - pci_read_config_byte(data.bridge, PCI_SUBORDINATE_BUS, &sub_bus); - dev_id.pci.shadow_bus_range.subordinate_bus =3D sub_bus; - } + pci_read_config_byte(data.bridge, PCI_SECONDARY_BUS, + &sec_bus); + hv_devid.pci.shadow_bus_range.secondary_bus =3D sec_bus; + pci_read_config_byte(data.bridge, PCI_SUBORDINATE_BUS, + &sub_bus); + hv_devid.pci.shadow_bus_range.subordinate_bus =3D sub_bus; } } =20 - return dev_id; +out: + return hv_devid; } =20 -/** - * hv_map_msi_interrupt() - "Map" the MSI IRQ in the hypervisor. +/* + * hv_map_msi_interrupt() - Map the MSI IRQ in the hypervisor. * @data: Describes the IRQ * @out_entry: Hypervisor (MSI) interrupt entry (can be NULL) * @@ -188,22 +189,23 @@ int hv_map_msi_interrupt(struct irq_data *data, { struct irq_cfg *cfg =3D irqd_cfg(data); struct hv_interrupt_entry dummy; - union hv_device_id device_id; + union hv_device_id hv_devid; struct msi_desc *msidesc; - struct pci_dev *dev; + struct pci_dev *pdev; int cpu; =20 msidesc =3D irq_data_get_msi_desc(data); - dev =3D msi_desc_to_pci_dev(msidesc); - device_id =3D hv_build_pci_dev_id(dev); + pdev =3D msi_desc_to_pci_dev(msidesc); + hv_devid =3D hv_build_devid_type_pci(pdev); cpu =3D cpumask_first(irq_data_get_effective_affinity_mask(data)); =20 - return hv_map_interrupt(device_id, false, cpu, cfg->vector, + return hv_map_interrupt(hv_devid, false, cpu, cfg->vector, out_entry ? out_entry : &dummy); } EXPORT_SYMBOL_GPL(hv_map_msi_interrupt); =20 -static inline void entry_to_msi_msg(struct hv_interrupt_entry *entry, stru= ct msi_msg *msg) +static void entry_to_msi_msg(struct hv_interrupt_entry *entry, + struct msi_msg *msg) { /* High address is always 0 */ msg->address_hi =3D 0; @@ -211,17 +213,19 @@ static inline void entry_to_msi_msg(struct hv_interru= pt_entry *entry, struct msi msg->data =3D entry->msi_entry.data.as_uint32; } =20 -static int hv_unmap_msi_interrupt(struct pci_dev *dev, struct hv_interrupt= _entry *old_entry); +static int hv_unmap_msi_interrupt(struct pci_dev *pdev, + struct hv_interrupt_entry *irq_entry); + static void hv_irq_compose_msi_msg(struct irq_data *data, struct msi_msg *= msg) { struct hv_interrupt_entry *stored_entry; struct irq_cfg *cfg =3D irqd_cfg(data); struct msi_desc *msidesc; - struct pci_dev *dev; + struct pci_dev *pdev; int ret; =20 msidesc =3D irq_data_get_msi_desc(data); - dev =3D msi_desc_to_pci_dev(msidesc); + pdev =3D msi_desc_to_pci_dev(msidesc); =20 if (!cfg) { pr_debug("%s: cfg is NULL", __func__); @@ -240,7 +244,7 @@ static void hv_irq_compose_msi_msg(struct irq_data *dat= a, struct msi_msg *msg) stored_entry =3D data->chip_data; data->chip_data =3D NULL; =20 - ret =3D hv_unmap_msi_interrupt(dev, stored_entry); + ret =3D hv_unmap_msi_interrupt(pdev, stored_entry); =20 kfree(stored_entry); =20 @@ -249,10 +253,8 @@ static void hv_irq_compose_msi_msg(struct irq_data *da= ta, struct msi_msg *msg) } =20 stored_entry =3D kzalloc_obj(*stored_entry, GFP_ATOMIC); - if (!stored_entry) { - pr_debug("%s: failed to allocate chip data\n", __func__); + if (!stored_entry) return; - } =20 ret =3D hv_map_msi_interrupt(data, stored_entry); if (ret) { @@ -262,18 +264,21 @@ static void hv_irq_compose_msi_msg(struct irq_data *d= ata, struct msi_msg *msg) =20 data->chip_data =3D stored_entry; entry_to_msi_msg(data->chip_data, msg); - - return; } =20 -static int hv_unmap_msi_interrupt(struct pci_dev *dev, struct hv_interrupt= _entry *old_entry) +static int hv_unmap_msi_interrupt(struct pci_dev *pdev, + struct hv_interrupt_entry *irq_entry) { - return hv_unmap_interrupt(hv_build_pci_dev_id(dev).as_uint64, old_entry); + union hv_device_id hv_devid; + + hv_devid =3D hv_build_devid_type_pci(pdev); + return hv_unmap_interrupt(hv_devid.as_uint64, irq_entry); } =20 -static void hv_teardown_msi_irq(struct pci_dev *dev, struct irq_data *irqd) +/* NB: during map, hv_interrupt_entry is saved via data->chip_data */ +static void hv_teardown_msi_irq(struct pci_dev *pdev, struct irq_data *irq= d) { - struct hv_interrupt_entry old_entry; + struct hv_interrupt_entry irq_entry; struct msi_msg msg; =20 if (!irqd->chip_data) { @@ -281,13 +286,13 @@ static void hv_teardown_msi_irq(struct pci_dev *dev, = struct irq_data *irqd) return; } =20 - old_entry =3D *(struct hv_interrupt_entry *)irqd->chip_data; - entry_to_msi_msg(&old_entry, &msg); + irq_entry =3D *(struct hv_interrupt_entry *)irqd->chip_data; + entry_to_msi_msg(&irq_entry, &msg); =20 kfree(irqd->chip_data); irqd->chip_data =3D NULL; =20 - (void)hv_unmap_msi_interrupt(dev, &old_entry); + (void)hv_unmap_msi_interrupt(pdev, &irq_entry); } =20 /* @@ -302,7 +307,8 @@ static struct irq_chip hv_pci_msi_controller =3D { }; =20 static bool hv_init_dev_msi_info(struct device *dev, struct irq_domain *do= main, - struct irq_domain *real_parent, struct msi_domain_info *info) + struct irq_domain *real_parent, + struct msi_domain_info *info) { struct irq_chip *chip =3D info->chip; =20 @@ -317,7 +323,8 @@ static bool hv_init_dev_msi_info(struct device *dev, st= ruct irq_domain *domain, } =20 #define HV_MSI_FLAGS_SUPPORTED (MSI_GENERIC_FLAGS_MASK | MSI_FLAG_PCI_MSIX) -#define HV_MSI_FLAGS_REQUIRED (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF= _CHIP_OPS) +#define HV_MSI_FLAGS_REQUIRED (MSI_FLAG_USE_DEF_DOM_OPS | \ + MSI_FLAG_USE_DEF_CHIP_OPS) =20 static struct msi_parent_ops hv_msi_parent_ops =3D { .supported_flags =3D HV_MSI_FLAGS_SUPPORTED, @@ -329,14 +336,14 @@ static struct msi_parent_ops hv_msi_parent_ops =3D { .init_dev_msi_info =3D hv_init_dev_msi_info, }; =20 -static int hv_msi_domain_alloc(struct irq_domain *d, unsigned int virq, un= signed int nr_irqs, - void *arg) +/* Allocate nr_irqs IRQs for the given irq domain */ +static int hv_msi_domain_alloc(struct irq_domain *d, unsigned int virq, + unsigned int nr_irqs, void *arg) { /* - * TODO: The allocation bits of hv_irq_compose_msi_msg(), i.e. everything= except - * entry_to_msi_msg() should be in here. + * TODO: The allocation bits of hv_irq_compose_msi_msg(), i.e. + * everything except entry_to_msi_msg() should be in here. */ - int ret; =20 ret =3D irq_domain_alloc_irqs_parent(d, virq, nr_irqs, arg); @@ -344,13 +351,15 @@ static int hv_msi_domain_alloc(struct irq_domain *d, = unsigned int virq, unsigned return ret; =20 for (int i =3D 0; i < nr_irqs; ++i) { - irq_domain_set_info(d, virq + i, 0, &hv_pci_msi_controller, NULL, - handle_edge_irq, NULL, "edge"); + irq_domain_set_info(d, virq + i, 0, &hv_pci_msi_controller, + NULL, handle_edge_irq, NULL, "edge"); } + return 0; } =20 -static void hv_msi_domain_free(struct irq_domain *d, unsigned int virq, un= signed int nr_irqs) +static void hv_msi_domain_free(struct irq_domain *d, unsigned int virq, + unsigned int nr_irqs) { for (int i =3D 0; i < nr_irqs; ++i) { struct irq_data *irqd =3D irq_domain_get_irq_data(d, virq); @@ -362,6 +371,7 @@ static void hv_msi_domain_free(struct irq_domain *d, un= signed int virq, unsigned =20 hv_teardown_msi_irq(to_pci_dev(desc->dev), irqd); } + irq_domain_free_irqs_top(d, virq, nr_irqs); } =20 @@ -394,25 +404,25 @@ struct irq_domain * __init hv_create_pci_msi_domain(v= oid) =20 int hv_unmap_ioapic_interrupt(int ioapic_id, struct hv_interrupt_entry *en= try) { - union hv_device_id device_id; + union hv_device_id hv_devid; =20 - device_id.as_uint64 =3D 0; - device_id.device_type =3D HV_DEVICE_TYPE_IOAPIC; - device_id.ioapic.ioapic_id =3D (u8)ioapic_id; + hv_devid.as_uint64 =3D 0; + hv_devid.device_type =3D HV_DEVICE_TYPE_IOAPIC; + hv_devid.ioapic.ioapic_id =3D (u8)ioapic_id; =20 - return hv_unmap_interrupt(device_id.as_uint64, entry); + return hv_unmap_interrupt(hv_devid.as_uint64, entry); } EXPORT_SYMBOL_GPL(hv_unmap_ioapic_interrupt); =20 int hv_map_ioapic_interrupt(int ioapic_id, bool level, int cpu, int vector, struct hv_interrupt_entry *entry) { - union hv_device_id device_id; + union hv_device_id hv_devid; =20 - device_id.as_uint64 =3D 0; - device_id.device_type =3D HV_DEVICE_TYPE_IOAPIC; - device_id.ioapic.ioapic_id =3D (u8)ioapic_id; + hv_devid.as_uint64 =3D 0; + hv_devid.device_type =3D HV_DEVICE_TYPE_IOAPIC; + hv_devid.ioapic.ioapic_id =3D (u8)ioapic_id; =20 - return hv_map_interrupt(device_id, level, cpu, vector, entry); + return hv_map_interrupt(hv_devid, level, cpu, vector, entry); } EXPORT_SYMBOL_GPL(hv_map_ioapic_interrupt); --=20 2.51.2.vfs.0.1 From nobody Fri Jun 12 22:47:19 2026 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 1FCEB2D949C; Tue, 12 May 2026 02:03:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=13.77.154.182 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778551402; cv=none; b=u0QjpKdzqRBdbpc9d8oo6cEguIyACmxuSaYggLHRuDfpMOmU4WXX4RyMV2Qo957QoPMNHNQ7q1hygKfsIRzEF40JrPL4JLg/9Yq1a3QoXKAIdn3c3ZaK4csFaO5o+M1JPn3MSpFMgysjlVzR3O05pNptGhlJzC0QuMoppzX94rE= ARC-Message-Signature: i=1; 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Mon, 11 May 2026 19:03:16 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 8099720B7178 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1778551397; bh=/NGej0120vNKqYpfLmvqutBNKpHH9eJZWzNxe7ny+6w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sFJJtMRJzlXARmHWxA5JylGBJN1o5Prfzs/w5iaD+r586N27gnTjG+EsnmfCpJyBg Kw6M3j2us0udwGfeBJizlxgDCWm2X35rpHG16mExOigjCrxdRIlxkIAkBzQBB1r5YS W6878jRwDne2Q6bZHpXJZzjUtfDOBZcGRlRkT8dU= From: Mukesh R To: hpa@zytor.com, robin.murphy@arm.com, robh@kernel.org, wei.liu@kernel.org, mrathor@linux.microsoft.com, mhklinux@outlook.com, muislam@microsoft.com, namjain@linux.microsoft.com, magnuskulke@linux.microsoft.com, anbelski@linux.microsoft.com, linux-kernel@vger.kernel.org, linux-hyperv@vger.kernel.org, iommu@lists.linux.dev, linux-pci@vger.kernel.org, linux-arch@vger.kernel.org Cc: kys@microsoft.com, haiyangz@microsoft.com, decui@microsoft.com, longli@microsoft.com, tglx@kernel.org, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, joro@8bytes.org, will@kernel.org, lpieralisi@kernel.org, kwilczynski@kernel.org, bhelgaas@google.com, arnd@arndb.de, jacob.pan@linux.microsoft.com Subject: [PATCH V3 03/11] mshv: Provide a way to get partition ID if running in a VMM process Date: Mon, 11 May 2026 19:02:51 -0700 Message-ID: <20260512020259.1678627-4-mrathor@linux.microsoft.com> X-Mailer: git-send-email 2.51.2.vfs.0.1 In-Reply-To: <20260512020259.1678627-1-mrathor@linux.microsoft.com> References: <20260512020259.1678627-1-mrathor@linux.microsoft.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Many PCI passthru related hypercalls require partition ID of the target guest. Guests are actually managed by MSHV driver and the partition ID is only maintained there. Add a field in the partition struct in MSHV driver to save the tgid of the VMM process creating the partition, and add a function there to retrieve partition ID if the current process is a VMM process. Reviewed-by: Anirudh Rayabharam (Microsoft) Signed-off-by: Mukesh R --- drivers/hv/mshv_root.h | 1 + drivers/hv/mshv_root_main.c | 22 ++++++++++++++++++++++ include/asm-generic/mshyperv.h | 5 +++++ 3 files changed, 28 insertions(+) diff --git a/drivers/hv/mshv_root.h b/drivers/hv/mshv_root.h index 1f086dcb7aa1..a85c24dcc701 100644 --- a/drivers/hv/mshv_root.h +++ b/drivers/hv/mshv_root.h @@ -138,6 +138,7 @@ struct mshv_partition { =20 struct mshv_girq_routing_table __rcu *pt_girq_tbl; u64 isolation_type; + pid_t pt_vmm_tgid; bool import_completed; bool pt_initialized; #if IS_ENABLED(CONFIG_DEBUG_FS) diff --git a/drivers/hv/mshv_root_main.c b/drivers/hv/mshv_root_main.c index bd1359eb58dd..02c107458be9 100644 --- a/drivers/hv/mshv_root_main.c +++ b/drivers/hv/mshv_root_main.c @@ -1908,6 +1908,27 @@ mshv_partition_release(struct inode *inode, struct f= ile *filp) return 0; } =20 +/* Given a process tgid, return partition id if it is a VMM process */ +u64 mshv_current_partid(void) +{ + struct mshv_partition *pt; + int i; + u64 ret_ptid =3D HV_PARTITION_ID_INVALID; + + rcu_read_lock(); + + hash_for_each_rcu(mshv_root.pt_htable, i, pt, pt_hnode) { + if (pt->pt_vmm_tgid =3D=3D current->tgid) { + ret_ptid =3D pt->pt_id; + break; + } + } + + rcu_read_unlock(); + return ret_ptid; +} +EXPORT_SYMBOL_GPL(mshv_current_partid); + static int add_partition(struct mshv_partition *partition) { @@ -2073,6 +2094,7 @@ mshv_ioctl_create_partition(void __user *user_arg, st= ruct device *module_dev) goto cleanup_irq_srcu; =20 partition->pt_id =3D pt_id; + partition->pt_vmm_tgid =3D current->tgid; =20 ret =3D add_partition(partition); if (ret) diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h index bf601d67cecb..e8cbc4e3f7ad 100644 --- a/include/asm-generic/mshyperv.h +++ b/include/asm-generic/mshyperv.h @@ -350,6 +350,7 @@ int hv_call_add_logical_proc(int node, u32 lp_index, u3= 2 acpi_id); int hv_call_notify_all_processors_started(void); bool hv_lp_exists(u32 lp_index); int hv_call_create_vp(int node, u64 partition_id, u32 vp_index, u32 flags); +u64 mshv_current_partid(void); =20 #else /* CONFIG_MSHV_ROOT */ static inline bool hv_root_partition(void) { return false; } @@ -380,6 +381,10 @@ static inline int hv_call_create_vp(int node, u64 part= ition_id, u32 vp_index, u3 { return -EOPNOTSUPP; } +static inline u64 mshv_current_partid(void) +{ + return HV_PARTITION_ID_INVALID; +} #endif /* CONFIG_MSHV_ROOT */ =20 static inline int hv_deposit_memory(u64 partition_id, u64 status) --=20 2.51.2.vfs.0.1 From nobody Fri Jun 12 22:47:19 2026 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id CA78A2BF002; Tue, 12 May 2026 02:03:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=13.77.154.182 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778551403; cv=none; b=cMg14dMTtv0KHVF9Q+pJTbmTL6rAPfOC9tRvpQNvT5VCJl7NLVOnhSsKLAH6Zr97KOOekAlqpwrXkfyU1zN3WkoDDe1puzuJyFUtKBSGLqXV/vsfrE91vXgrtZ1Ix1tie/Yiv49Fx7le4nKzCUMlIkVC5DUAaykHMPhB6k0VS8w= ARC-Message-Signature: i=1; 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Mon, 11 May 2026 19:03:18 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 3548E20B717A DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1778551399; bh=sI1uTfyi7YwzdcnjBG4TUNpa5h8tmdGMVODypA3HaLw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gz1rp8sjS0vih/Cy1h28uTb2gKzQOj37xv7arKHVjWwN1anTX8TAcTixcXtXXUll+ GGcpgVx9VSFcfuCvcayXowkqnqYdJSMv1xOqWw1nvFv9AZitG5PbC+WSqffR24aMt4 b/F+oroxSP2yDt3i5vXaQUhjOYbKfldS1HHtE9hU= From: Mukesh R To: hpa@zytor.com, robin.murphy@arm.com, robh@kernel.org, wei.liu@kernel.org, mrathor@linux.microsoft.com, mhklinux@outlook.com, muislam@microsoft.com, namjain@linux.microsoft.com, magnuskulke@linux.microsoft.com, anbelski@linux.microsoft.com, linux-kernel@vger.kernel.org, linux-hyperv@vger.kernel.org, iommu@lists.linux.dev, linux-pci@vger.kernel.org, linux-arch@vger.kernel.org Cc: kys@microsoft.com, haiyangz@microsoft.com, decui@microsoft.com, longli@microsoft.com, tglx@kernel.org, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, joro@8bytes.org, will@kernel.org, lpieralisi@kernel.org, kwilczynski@kernel.org, bhelgaas@google.com, arnd@arndb.de, jacob.pan@linux.microsoft.com Subject: [PATCH V3 04/11] mshv: Declarations and definitions for VFIO-MSHV bridge device Date: Mon, 11 May 2026 19:02:52 -0700 Message-ID: <20260512020259.1678627-5-mrathor@linux.microsoft.com> X-Mailer: git-send-email 2.51.2.vfs.0.1 In-Reply-To: <20260512020259.1678627-1-mrathor@linux.microsoft.com> References: <20260512020259.1678627-1-mrathor@linux.microsoft.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Add data structs needed by the subsequent patch that introduces a new module to implement VFIO-MSHV pseudo device. Signed-off-by: Mukesh R Reviewed-by: Souradeep Chakrabarti --- drivers/hv/mshv_root.h | 19 +++++++++++++++++++ include/uapi/linux/mshv.h | 30 ++++++++++++++++++++++++++++++ 2 files changed, 49 insertions(+) diff --git a/drivers/hv/mshv_root.h b/drivers/hv/mshv_root.h index a85c24dcc701..b9880d0bdc4d 100644 --- a/drivers/hv/mshv_root.h +++ b/drivers/hv/mshv_root.h @@ -227,6 +227,25 @@ struct port_table_info { }; }; =20 +struct mshv_device { + const struct mshv_device_ops *device_ops; + struct mshv_partition *device_pt; + void *device_private; + struct hlist_node device_ptnode; +}; + +struct mshv_device_ops { + const char *device_name; + long (*device_create)(struct mshv_device *dev); + void (*device_release)(struct mshv_device *dev); + long (*device_set_attr)(struct mshv_device *dev, + struct mshv_device_attr *attr); + long (*device_has_attr)(struct mshv_device *dev, + struct mshv_device_attr *attr); +}; + +extern struct mshv_device_ops mshv_vfio_device_ops; + int mshv_update_routing_table(struct mshv_partition *partition, const struct mshv_user_irq_entry *entries, unsigned int numents); diff --git a/include/uapi/linux/mshv.h b/include/uapi/linux/mshv.h index 32ff92b6342b..be6fe3ee8707 100644 --- a/include/uapi/linux/mshv.h +++ b/include/uapi/linux/mshv.h @@ -404,4 +404,34 @@ struct mshv_sint_mask { /* hv_hvcall device */ #define MSHV_HVCALL_SETUP _IOW(MSHV_IOCTL, 0x1E, struct mshv_vtl_hv= call_setup) #define MSHV_HVCALL _IOWR(MSHV_IOCTL, 0x1F, struct mshv_vtl_h= vcall) + +/* Device passhthru */ +#define MSHV_CREATE_DEVICE_TEST 1 + +enum { + MSHV_DEV_TYPE_VFIO, + MSHV_DEV_TYPE_MAX, +}; + +struct mshv_create_device { + __u32 type; /* in: MSHV_DEV_TYPE_xxx */ + __u32 fd; /* out: device handle */ + __u32 flags; /* in: MSHV_CREATE_DEVICE_xxx */ +}; + +#define MSHV_DEV_VFIO_FILE 1 +#define MSHV_DEV_VFIO_FILE_ADD 1 +#define MSHV_DEV_VFIO_FILE_DEL 2 + +struct mshv_device_attr { + __u32 flags; /* no flags currently defined */ + __u32 group; /* device-defined */ + __u64 attr; /* group-defined */ + __u64 addr; /* userspace address of attr data */ +}; + +/* Device fds created with MSHV_CREATE_DEVICE */ +#define MSHV_SET_DEVICE_ATTR _IOW(MSHV_IOCTL, 0x00, struct mshv_device_att= r) +#define MSHV_HAS_DEVICE_ATTR _IOW(MSHV_IOCTL, 0x01, struct mshv_device_att= r) + #endif --=20 2.51.2.vfs.0.1 From nobody Fri Jun 12 22:47:19 2026 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 580632D7812; Tue, 12 May 2026 02:03:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=13.77.154.182 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778551405; cv=none; b=Kkj9HebQ+nm1jwej27AzzY4WBdzvrLKE18veGBPqvhN2jrX8qTa7uK8UYZSpGjQ0WYF4fZEfirr6tKujhsw+OF7ETmuPzpI08ymG70gj/r+Q9jkIjwUjeVkRCdJU4dnQWWyUVHcTBiPsC64XH44IuTSXP3P9blTIFskHTuqqq0s= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778551405; c=relaxed/simple; bh=cKNmu5kTnn04IlU0+uGx8nFTijByejUaTMVt4ltTx5A=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=nrkQ86iuVdoygVu+OB0NSp0JmutPLPCa+sh1xjvYUitsNZvPNvdY/n3gacuqf1D9xJ/mj7pI6q8gkAKnuQvtX5otCw1kV8YXGgVVc9J9HZSZ/BuxnLuULrgRynO8Jel6mKKn54FrphaghG/smdvj6DJ/ldLFJaBYQbS9jXt7kiE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com; spf=pass smtp.mailfrom=linux.microsoft.com; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b=bD+tslee; arc=none smtp.client-ip=13.77.154.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="bD+tslee" Received: from mrdev.corp.microsoft.com (unknown [13.88.17.9]) by linux.microsoft.com (Postfix) with ESMTPSA id F08C720B7169; Mon, 11 May 2026 19:03:19 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com F08C720B7169 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1778551400; bh=5AUWmMSE9er8oWtWVdhLYfhBV62m5YIK8L9e8/xH+o0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bD+tsleeoUrmJPtjyj0ISriWIzzCOckDXpIS/7xvyWwNyIceA+MjeHPLEZlF2zs4c YgKSTcySxmupLiWCW5kYybLWGm0KiNq7Nkq5pWqaM/UWMa5Aj+8EBSs3ZCZKLnHxDu LGQfyhioa8fVcPoIwPhuxG8VCq7pYk9ITmDpgtmY= From: Mukesh R To: hpa@zytor.com, robin.murphy@arm.com, robh@kernel.org, wei.liu@kernel.org, mrathor@linux.microsoft.com, mhklinux@outlook.com, muislam@microsoft.com, namjain@linux.microsoft.com, magnuskulke@linux.microsoft.com, anbelski@linux.microsoft.com, linux-kernel@vger.kernel.org, linux-hyperv@vger.kernel.org, iommu@lists.linux.dev, linux-pci@vger.kernel.org, linux-arch@vger.kernel.org Cc: kys@microsoft.com, haiyangz@microsoft.com, decui@microsoft.com, longli@microsoft.com, tglx@kernel.org, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, joro@8bytes.org, will@kernel.org, lpieralisi@kernel.org, kwilczynski@kernel.org, bhelgaas@google.com, arnd@arndb.de, jacob.pan@linux.microsoft.com Subject: [PATCH V3 05/11] mshv: Implement mshv bridge device for VFIO Date: Mon, 11 May 2026 19:02:53 -0700 Message-ID: <20260512020259.1678627-6-mrathor@linux.microsoft.com> X-Mailer: git-send-email 2.51.2.vfs.0.1 In-Reply-To: <20260512020259.1678627-1-mrathor@linux.microsoft.com> References: <20260512020259.1678627-1-mrathor@linux.microsoft.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Add a new file to implement VFIO-MSHV bridge pseudo device. These functions are called in the VFIO framework, and credits to kvm/vfio.c as this file was adapted from it. Co-developed-by: Wei Liu Signed-off-by: Wei Liu Signed-off-by: Mukesh R --- drivers/hv/Makefile | 3 +- drivers/hv/mshv_vfio.c | 211 ++++++++++++++++++++++++++++++++++++++ include/uapi/linux/mshv.h | 1 + 3 files changed, 214 insertions(+), 1 deletion(-) create mode 100644 drivers/hv/mshv_vfio.c diff --git a/drivers/hv/Makefile b/drivers/hv/Makefile index 888a748cc7cb..9ab6fc254c38 100644 --- a/drivers/hv/Makefile +++ b/drivers/hv/Makefile @@ -14,7 +14,8 @@ hv_vmbus-y :=3D vmbus_drv.o \ hv_vmbus-$(CONFIG_HYPERV_TESTING) +=3D hv_debugfs.o hv_utils-y :=3D hv_util.o hv_kvp.o hv_snapshot.o hv_utils_transport.o mshv_root-y :=3D mshv_root_main.o mshv_synic.o mshv_eventfd.o mshv_irq.o \ - mshv_root_hv_call.o mshv_portid_table.o mshv_regions.o + mshv_root_hv_call.o mshv_portid_table.o mshv_regions.o \ + mshv_vfio.o mshv_root-$(CONFIG_DEBUG_FS) +=3D mshv_debugfs.o mshv_root-$(CONFIG_TRACEPOINTS) +=3D mshv_trace.o mshv_vtl-y :=3D mshv_vtl_main.o diff --git a/drivers/hv/mshv_vfio.c b/drivers/hv/mshv_vfio.c new file mode 100644 index 000000000000..00a97920e25b --- /dev/null +++ b/drivers/hv/mshv_vfio.c @@ -0,0 +1,211 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * VFIO-MSHV bridge pseudo device + * + * Heavily inspired by the VFIO-KVM bridge pseudo device. + */ +#include +#include +#include +#include +#include +#include +#include +#include + +#include "mshv.h" +#include "mshv_root.h" + +struct mshv_vfio_file { + struct list_head node; + struct file *file; /* list of struct mshv_vfio_file */ +}; + +struct mshv_vfio { + struct list_head file_list; + struct mutex lock; +}; + +static bool mshv_vfio_file_is_valid(struct file *file) +{ + bool (*fn)(struct file *file); + bool ret; + + fn =3D symbol_get(vfio_file_is_valid); + if (!fn) + return false; + + ret =3D fn(file); + + symbol_put(vfio_file_is_valid); + + return ret; +} + +static long mshv_vfio_file_add(struct mshv_device *mshvdev, unsigned int f= d) +{ + struct mshv_vfio *mshv_vfio =3D mshvdev->device_private; + struct mshv_vfio_file *mvf; + struct file *filp; + long ret =3D 0; + + filp =3D fget(fd); + if (!filp) + return -EBADF; + + /* Ensure the FD is a vfio FD. */ + if (!mshv_vfio_file_is_valid(filp)) { + ret =3D -EINVAL; + goto out_fput; + } + + mutex_lock(&mshv_vfio->lock); + + list_for_each_entry(mvf, &mshv_vfio->file_list, node) { + if (mvf->file =3D=3D filp) { + ret =3D -EEXIST; + goto out_unlock; + } + } + + mvf =3D kzalloc(sizeof(*mvf), GFP_KERNEL_ACCOUNT); + if (!mvf) { + ret =3D -ENOMEM; + goto out_unlock; + } + + mvf->file =3D get_file(filp); + list_add_tail(&mvf->node, &mshv_vfio->file_list); + +out_unlock: + mutex_unlock(&mshv_vfio->lock); +out_fput: + fput(filp); + return ret; +} + +static long mshv_vfio_file_del(struct mshv_device *mshvdev, unsigned int f= d) +{ + struct mshv_vfio *mshv_vfio =3D mshvdev->device_private; + struct mshv_vfio_file *mvf; + long ret; + + CLASS(fd, f)(fd); + + if (fd_empty(f)) + return -EBADF; + + ret =3D -ENOENT; + mutex_lock(&mshv_vfio->lock); + + list_for_each_entry(mvf, &mshv_vfio->file_list, node) { + if (mvf->file !=3D fd_file(f)) + continue; + + list_del(&mvf->node); + fput(mvf->file); + kfree(mvf); + ret =3D 0; + break; + } + + mutex_unlock(&mshv_vfio->lock); + return ret; +} + +static long mshv_vfio_set_file(struct mshv_device *mshvdev, long attr, + void __user *arg) +{ + int32_t __user *argp =3D arg; + int32_t fd; + + switch (attr) { + case MSHV_DEV_VFIO_FILE_ADD: + if (get_user(fd, argp)) + return -EFAULT; + return mshv_vfio_file_add(mshvdev, fd); + + case MSHV_DEV_VFIO_FILE_DEL: + if (get_user(fd, argp)) + return -EFAULT; + return mshv_vfio_file_del(mshvdev, fd); + } + + return -ENXIO; +} + +static long mshv_vfio_set_attr(struct mshv_device *mshvdev, + struct mshv_device_attr *attr) +{ + switch (attr->group) { + case MSHV_DEV_VFIO_FILE: + return mshv_vfio_set_file(mshvdev, attr->attr, + u64_to_user_ptr(attr->addr)); + } + + return -ENXIO; +} + +static long mshv_vfio_has_attr(struct mshv_device *mshvdev, + struct mshv_device_attr *attr) +{ + switch (attr->group) { + case MSHV_DEV_VFIO_FILE: + switch (attr->attr) { + case MSHV_DEV_VFIO_FILE_ADD: + case MSHV_DEV_VFIO_FILE_DEL: + return 0; + } + + break; + } + + return -ENXIO; +} + +static long mshv_vfio_create_device(struct mshv_device *mshvdev) +{ + struct mshv_device *tmp; + struct mshv_vfio *mshv_vfio; + + /* Only one VFIO "device" per VM */ + hlist_for_each_entry(tmp, &mshvdev->device_pt->pt_devices, + device_ptnode) + if (tmp->device_ops =3D=3D &mshv_vfio_device_ops) + return -EBUSY; + + mshv_vfio =3D kzalloc(sizeof(*mshv_vfio), GFP_KERNEL_ACCOUNT); + if (mshv_vfio =3D=3D NULL) + return -ENOMEM; + + INIT_LIST_HEAD(&mshv_vfio->file_list); + mutex_init(&mshv_vfio->lock); + + mshvdev->device_private =3D mshv_vfio; + + return 0; +} + +/* This is called from mshv_device_fop_release() */ +static void mshv_vfio_release_device(struct mshv_device *mshvdev) +{ + struct mshv_vfio *mv =3D mshvdev->device_private; + struct mshv_vfio_file *mvf, *tmp; + + list_for_each_entry_safe(mvf, tmp, &mv->file_list, node) { + fput(mvf->file); + list_del(&mvf->node); + kfree(mvf); + } + + kfree(mv); + kfree(mshvdev); +} + +struct mshv_device_ops mshv_vfio_device_ops =3D { + .device_name =3D "mshv-vfio", + .device_create =3D mshv_vfio_create_device, + .device_release =3D mshv_vfio_release_device, + .device_set_attr =3D mshv_vfio_set_attr, + .device_has_attr =3D mshv_vfio_has_attr, +}; diff --git a/include/uapi/linux/mshv.h b/include/uapi/linux/mshv.h index be6fe3ee8707..b038a79786d2 100644 --- a/include/uapi/linux/mshv.h +++ b/include/uapi/linux/mshv.h @@ -254,6 +254,7 @@ struct mshv_root_hvcall { #define MSHV_GET_GPAP_ACCESS_BITMAP _IOWR(MSHV_IOCTL, 0x06, struct mshv_gp= ap_access_bitmap) /* Generic hypercall */ #define MSHV_ROOT_HVCALL _IOWR(MSHV_IOCTL, 0x07, struct mshv_root_hvcall) +#define MSHV_CREATE_DEVICE _IOWR(MSHV_IOCTL, 0x08, struct mshv= _create_device) =20 /* ******************************** --=20 2.51.2.vfs.0.1 From nobody Fri Jun 12 22:47:19 2026 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 06A7A23BCEE; 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arc=none smtp.client-ip=13.77.154.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="LOF48eh8" Received: from mrdev.corp.microsoft.com (unknown [13.88.17.9]) by linux.microsoft.com (Postfix) with ESMTPSA id 792FE20B716A; Mon, 11 May 2026 19:03:21 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 792FE20B716A DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1778551402; bh=torw1rFNIs6S4jLC1p2Rij05fcbQgV06MR8D7ovym88=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LOF48eh8QCooC945Kl5BQDQbB1Fg4jyVCy1KbgjJKtpfACB6QHFkmlzFnz7mEiMhE Pt3v8XwEl/64KIKS5hz4ucaOUQsNaoEc66BKo58jKN6J+nkgr26JoU+RKwgE0dQOgy ykJs27OeuVHvtRZf4p3zVXyiJh9B4h8PiD1oMNz8= From: Mukesh R To: hpa@zytor.com, robin.murphy@arm.com, robh@kernel.org, wei.liu@kernel.org, mrathor@linux.microsoft.com, mhklinux@outlook.com, muislam@microsoft.com, namjain@linux.microsoft.com, magnuskulke@linux.microsoft.com, anbelski@linux.microsoft.com, linux-kernel@vger.kernel.org, linux-hyperv@vger.kernel.org, iommu@lists.linux.dev, linux-pci@vger.kernel.org, linux-arch@vger.kernel.org Cc: kys@microsoft.com, haiyangz@microsoft.com, decui@microsoft.com, longli@microsoft.com, tglx@kernel.org, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, joro@8bytes.org, will@kernel.org, lpieralisi@kernel.org, kwilczynski@kernel.org, bhelgaas@google.com, arnd@arndb.de, jacob.pan@linux.microsoft.com Subject: [PATCH V3 06/11] mshv: Add ioctl support for MSHV-VFIO bridge device Date: Mon, 11 May 2026 19:02:54 -0700 Message-ID: <20260512020259.1678627-7-mrathor@linux.microsoft.com> X-Mailer: git-send-email 2.51.2.vfs.0.1 In-Reply-To: <20260512020259.1678627-1-mrathor@linux.microsoft.com> References: <20260512020259.1678627-1-mrathor@linux.microsoft.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Add ioctl support for creating MSHV devices for a partition. At present only VFIO device types are supported, but more could be added. At a high level, a partition ioctl to create device verifies it is of type VFIO and does some setup for bridge code in mshv_vfio.c. Adapted from KVM device ioctls. Co-developed-by: Wei Liu Signed-off-by: Wei Liu Signed-off-by: Mukesh R --- drivers/hv/mshv_root_main.c | 116 ++++++++++++++++++++++++++++++++++++ 1 file changed, 116 insertions(+) diff --git a/drivers/hv/mshv_root_main.c b/drivers/hv/mshv_root_main.c index 02c107458be9..6ceb5f608589 100644 --- a/drivers/hv/mshv_root_main.c +++ b/drivers/hv/mshv_root_main.c @@ -1625,6 +1625,119 @@ mshv_partition_ioctl_initialize(struct mshv_partiti= on *partition) return ret; } =20 +static long mshv_device_attr_ioctl(struct mshv_device *mshv_dev, int cmd, + ulong uarg) +{ + struct mshv_device_attr attr; + const struct mshv_device_ops *devops =3D mshv_dev->device_ops; + + if (copy_from_user(&attr, (void __user *)uarg, sizeof(attr))) + return -EFAULT; + + switch (cmd) { + case MSHV_SET_DEVICE_ATTR: + if (devops->device_set_attr) + return devops->device_set_attr(mshv_dev, &attr); + break; + case MSHV_HAS_DEVICE_ATTR: + if (devops->device_has_attr) + return devops->device_has_attr(mshv_dev, &attr); + break; + } + + return -EPERM; +} + +static long mshv_device_fop_ioctl(struct file *filp, unsigned int cmd, + ulong uarg) +{ + struct mshv_device *mshv_dev =3D filp->private_data; + + switch (cmd) { + case MSHV_SET_DEVICE_ATTR: + case MSHV_HAS_DEVICE_ATTR: + return mshv_device_attr_ioctl(mshv_dev, cmd, uarg); + } + + return -ENOTTY; +} + +static int mshv_device_fop_release(struct inode *inode, struct file *filp) +{ + struct mshv_device *mshv_dev =3D filp->private_data; + struct mshv_partition *partition =3D mshv_dev->device_pt; + + if (mshv_dev->device_ops->device_release) { + mutex_lock(&partition->pt_mutex); + hlist_del(&mshv_dev->device_ptnode); + mshv_dev->device_ops->device_release(mshv_dev); + mutex_unlock(&partition->pt_mutex); + } + + mshv_partition_put(partition); + return 0; +} + +static const struct file_operations mshv_device_fops =3D { + .owner =3D THIS_MODULE, + .unlocked_ioctl =3D mshv_device_fop_ioctl, + .release =3D mshv_device_fop_release, +}; + +static long mshv_partition_ioctl_create_device(struct mshv_partition *part= ition, + void __user *uarg) +{ + long rc; + struct mshv_create_device devargk; + struct mshv_device *mshv_dev; + const struct mshv_device_ops *vfio_ops; + + if (copy_from_user(&devargk, uarg, sizeof(devargk))) + return -EFAULT; + + /* At present, only VFIO is supported */ + if (devargk.type !=3D MSHV_DEV_TYPE_VFIO) + return -ENODEV; + + if (devargk.flags & MSHV_CREATE_DEVICE_TEST) + return 0; + + /* This is freed later by mshv_vfio_release_device() */ + mshv_dev =3D kzalloc(sizeof(*mshv_dev), GFP_KERNEL_ACCOUNT); + if (mshv_dev =3D=3D NULL) + return -ENOMEM; + + vfio_ops =3D &mshv_vfio_device_ops; + mshv_dev->device_ops =3D vfio_ops; + mshv_dev->device_pt =3D partition; + + rc =3D vfio_ops->device_create(mshv_dev); + if (rc < 0) { + kfree(mshv_dev); + return rc; + } + + hlist_add_head(&mshv_dev->device_ptnode, &partition->pt_devices); + + mshv_partition_get(partition); + rc =3D anon_inode_getfd(vfio_ops->device_name, &mshv_device_fops, + mshv_dev, O_RDWR | O_CLOEXEC); + if (rc < 0) + goto undo_out; + + devargk.fd =3D rc; + if (copy_to_user(uarg, &devargk, sizeof(devargk))) + return -EFAULT; /* cleanup in mshv_device_fop_release() */ + + return 0; + +undo_out: + hlist_del(&mshv_dev->device_ptnode); + vfio_ops->device_release(mshv_dev); /* will kfree(mshv_dev) */ + mshv_partition_put(partition); + return rc; +} + static long mshv_partition_ioctl(struct file *filp, unsigned int ioctl, unsigned long = arg) { @@ -1661,6 +1774,9 @@ mshv_partition_ioctl(struct file *filp, unsigned int = ioctl, unsigned long arg) case MSHV_ROOT_HVCALL: ret =3D mshv_ioctl_passthru_hvcall(partition, true, uarg); break; + case MSHV_CREATE_DEVICE: + ret =3D mshv_partition_ioctl_create_device(partition, uarg); + break; default: ret =3D -ENOTTY; } --=20 2.51.2.vfs.0.1 From nobody Fri Jun 12 22:47:19 2026 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 20B1830BF70; Tue, 12 May 2026 02:03:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=13.77.154.182 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; 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spf=pass smtp.mailfrom=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="eJvq1b+a" Received: from mrdev.corp.microsoft.com (unknown [13.88.17.9]) by linux.microsoft.com (Postfix) with ESMTPSA id 2060420B716D; Mon, 11 May 2026 19:03:23 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 2060420B716D DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1778551404; bh=0bjgMj0k5nPoMwets23GFJzSwvZMJJftuqSY4+V25iQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=eJvq1b+aDvbibb6LAdPAwnKT8sRwG5ZxDZUlR3f6jRYzwDsK04xh5GsdzABZjJk1P LY3QVXZsY9U5X4G8bApta2SkQPA3tbt1QdGK9owniXK7jw2SfoPIywdmAJ4fGOpWgX p/AJjULg0x+uoaxTMaqeRSftkUSRQa9ILvaflG3o= From: Mukesh R To: hpa@zytor.com, robin.murphy@arm.com, robh@kernel.org, wei.liu@kernel.org, mrathor@linux.microsoft.com, mhklinux@outlook.com, muislam@microsoft.com, namjain@linux.microsoft.com, magnuskulke@linux.microsoft.com, anbelski@linux.microsoft.com, linux-kernel@vger.kernel.org, linux-hyperv@vger.kernel.org, iommu@lists.linux.dev, linux-pci@vger.kernel.org, linux-arch@vger.kernel.org Cc: kys@microsoft.com, haiyangz@microsoft.com, decui@microsoft.com, longli@microsoft.com, tglx@kernel.org, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, joro@8bytes.org, will@kernel.org, lpieralisi@kernel.org, kwilczynski@kernel.org, bhelgaas@google.com, arnd@arndb.de, jacob.pan@linux.microsoft.com Subject: [PATCH V3 07/11] mshv: Import data structs around device passthru from hyperv headers Date: Mon, 11 May 2026 19:02:55 -0700 Message-ID: <20260512020259.1678627-8-mrathor@linux.microsoft.com> X-Mailer: git-send-email 2.51.2.vfs.0.1 In-Reply-To: <20260512020259.1678627-1-mrathor@linux.microsoft.com> References: <20260512020259.1678627-1-mrathor@linux.microsoft.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Copy/import from Hyper-V public headers, definitions and declarations that are related to attaching and detaching of device domains, and building device ids for those purposes. Signed-off-by: Mukesh R --- include/hyperv/hvgdk_mini.h | 11 ++++ include/hyperv/hvhdk_mini.h | 112 ++++++++++++++++++++++++++++++++++++ 2 files changed, 123 insertions(+) diff --git a/include/hyperv/hvgdk_mini.h b/include/hyperv/hvgdk_mini.h index 6a4e8b9d570f..da622fb06440 100644 --- a/include/hyperv/hvgdk_mini.h +++ b/include/hyperv/hvgdk_mini.h @@ -326,6 +326,9 @@ union hv_hypervisor_version_info { /* stimer Direct Mode is available */ #define HV_STIMER_DIRECT_MODE_AVAILABLE BIT(19) =20 +#define HV_DEVICE_DOMAIN_AVAILABLE BIT(24) +#define HV_S1_DEVICE_DOMAIN_AVAILABLE BIT(25) + /* * Implementation recommendations. Indicates which behaviors the hypervisor * recommends the OS implement for optimal performance. @@ -475,6 +478,8 @@ union hv_vp_assist_msr_contents { /* HV_REGISTER_VP_AS= SIST_PAGE */ #define HVCALL_MAP_DEVICE_INTERRUPT 0x007c #define HVCALL_UNMAP_DEVICE_INTERRUPT 0x007d #define HVCALL_RETARGET_INTERRUPT 0x007e +#define HVCALL_ATTACH_DEVICE 0x0082 +#define HVCALL_DETACH_DEVICE 0x0083 #define HVCALL_NOTIFY_PARTITION_EVENT 0x0087 #define HVCALL_ENTER_SLEEP_STATE 0x0084 #define HVCALL_NOTIFY_PORT_RING_EMPTY 0x008b @@ -486,9 +491,15 @@ union hv_vp_assist_msr_contents { /* HV_REGISTER_VP_A= SSIST_PAGE */ #define HVCALL_GET_VP_INDEX_FROM_APIC_ID 0x009a #define HVCALL_FLUSH_GUEST_PHYSICAL_ADDRESS_SPACE 0x00af #define HVCALL_FLUSH_GUEST_PHYSICAL_ADDRESS_LIST 0x00b0 +#define HVCALL_CREATE_DEVICE_DOMAIN 0x00b1 +#define HVCALL_ATTACH_DEVICE_DOMAIN 0x00b2 +#define HVCALL_MAP_DEVICE_GPA_PAGES 0x00b3 +#define HVCALL_UNMAP_DEVICE_GPA_PAGES 0x00b4 #define HVCALL_SIGNAL_EVENT_DIRECT 0x00c0 #define HVCALL_POST_MESSAGE_DIRECT 0x00c1 #define HVCALL_DISPATCH_VP 0x00c2 +#define HVCALL_DETACH_DEVICE_DOMAIN 0x00c4 +#define HVCALL_DELETE_DEVICE_DOMAIN 0x00c5 #define HVCALL_GET_GPA_PAGES_ACCESS_STATES 0x00c9 #define HVCALL_ACQUIRE_SPARSE_SPA_PAGE_HOST_ACCESS 0x00d7 #define HVCALL_RELEASE_SPARSE_SPA_PAGE_HOST_ACCESS 0x00d8 diff --git a/include/hyperv/hvhdk_mini.h b/include/hyperv/hvhdk_mini.h index b4cb2fa26e9b..60425052a799 100644 --- a/include/hyperv/hvhdk_mini.h +++ b/include/hyperv/hvhdk_mini.h @@ -468,6 +468,32 @@ struct hv_send_ipi_ex { /* HV_INPUT_SEND_SYNTHETIC_CLU= STER_IPI_EX */ struct hv_vpset vp_set; } __packed; =20 +union hv_attdev_flags { /* HV_ATTACH_DEVICE_FLAGS */ + struct { + u32 logical_id : 1; + u32 resvd0 : 1; + u32 ats_enabled : 1; + u32 virt_func : 1; + u32 shared_irq_child : 1; + u32 virt_dev : 1; + u32 ats_supported : 1; + u32 small_irt : 1; + u32 resvd : 24; + } __packed; + u32 as_uint32; +}; + +union hv_dev_pci_caps { /* HV_DEVICE_PCI_CAPABILITIES */ + struct { + u32 max_pasid_width : 5; + u32 invalidate_qdepth : 5; + u32 global_inval : 1; + u32 prg_response_req : 1; + u32 resvd : 20; + } __packed; + u32 as_uint32; +}; + typedef u16 hv_pci_rid; /* HV_PCI_RID */ typedef u16 hv_pci_segment; /* HV_PCI_SEGMENT */ typedef u64 hv_logical_device_id; @@ -547,4 +573,90 @@ union hv_device_id { /* HV_DEVICE_ID */ } acpi; } __packed; =20 +struct hv_input_attach_device { /* HV_INPUT_ATTACH_DEVICE */ + u64 partition_id; + union hv_device_id device_id; + union hv_attdev_flags attdev_flags; + u8 attdev_vtl; + u8 rsvd0; + u16 rsvd1; + u64 logical_devid; + union hv_dev_pci_caps dev_pcicaps; + u16 pf_pci_rid; + u16 resvd2; +} __packed; + +struct hv_input_detach_device { /* HV_INPUT_DETACH_DEVICE */ + u64 partition_id; + u64 logical_devid; +} __packed; + + +/* 3 domain types: stage 1, stage 2, and SOC */ +#define HV_DEVICE_DOMAIN_TYPE_S2 0 /* HV_DEVICE_DOMAIN_ID_TYPE_S2 */ +#define HV_DEVICE_DOMAIN_TYPE_S1 1 /* HV_DEVICE_DOMAIN_ID_TYPE_S1 */ +#define HV_DEVICE_DOMAIN_TYPE_SOC 2 /* HV_DEVICE_DOMAIN_ID_TYPE_SOC */ + +/* ID for stage 2 default domain and NULL domain */ +#define HV_DEVICE_DOMAIN_ID_S2_DEFAULT 0 +#define HV_DEVICE_DOMAIN_ID_S2_NULL 0xFFFFFFFFULL + +union hv_device_domain_id { + u64 as_uint64; + struct { + u32 type : 4; + u32 reserved : 28; + u32 id; + }; +} __packed; + +struct hv_input_device_domain { /* HV_INPUT_DEVICE_DOMAIN */ + u64 partition_id; + union hv_input_vtl owner_vtl; + u8 padding[7]; + union hv_device_domain_id domain_id; +} __packed; + +union hv_create_device_domain_flags { /* HV_CREATE_DEVICE_DOMAIN_FLAGS */ + u32 as_uint32; + struct { + u32 forward_progress_required : 1; + u32 inherit_owning_vtl : 1; + u32 reserved : 30; + } __packed; +} __packed; + +struct hv_input_create_device_domain { /* HV_INPUT_CREATE_DEVICE_DOMAIN */ + struct hv_input_device_domain device_domain; + union hv_create_device_domain_flags create_device_domain_flags; +} __packed; + +struct hv_input_delete_device_domain { /* HV_INPUT_DELETE_DEVICE_DOMAIN */ + struct hv_input_device_domain device_domain; +} __packed; + +struct hv_input_attach_device_domain { /* HV_INPUT_ATTACH_DEVICE_DOMAIN */ + struct hv_input_device_domain device_domain; + union hv_device_id device_id; +} __packed; + +struct hv_input_detach_device_domain { /* HV_INPUT_DETACH_DEVICE_DOMAIN */ + u64 partition_id; + union hv_device_id device_id; +} __packed; + +struct hv_input_map_device_gpa_pages { /* HV_INPUT_MAP_DEVICE_GPA_PAGES */ + struct hv_input_device_domain device_domain; + union hv_input_vtl target_vtl; + u8 padding[3]; + u32 map_flags; + u64 target_device_va_base; + u64 gpa_page_list[]; +} __packed; + +struct hv_input_unmap_device_gpa_pages { /* HV_INPUT_UNMAP_DEVICE_GPA_PAG= ES */ + struct hv_input_device_domain device_domain; + u64 target_device_va_base; +} __packed; + #endif /* _HV_HVHDK_MINI_H */ --=20 2.51.2.vfs.0.1 From nobody Fri Jun 12 22:47:19 2026 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 7B8042FD1A5; Tue, 12 May 2026 02:03:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=13.77.154.182 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778551411; cv=none; b=a5EltR7R4UNnBkOLm3/3rk3BEuFAXb/Y8qlwpHu4F6K25PptBvBErctfJjxcfzYQ0kSZ7DQrWDiGCr3E7a06Y9aUVJRJmhWKtEcNhPe0H2CyoMlYR1I7q0JW0XFBuSCBlZEp/Gm9qWevD8FwoQ3C/3drtQQFe2DljWqxhzHvLaU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778551411; c=relaxed/simple; bh=4mr06T6EP6Cpty4TcmvEjQixPyKShwLmUzz2L06IFus=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ny1jWSrjiqdD6Hwcy7uGXduxvwIYENV2dAwUYArm4FirJGIzyRp4uajcqh371YKntRV5V8/pulM/L3spuqo6EgK5hhy8mh+3H25SYZgeWYOE04ppUpYWYzp2d8Q3CGA5fzWDwh6WwH067utU4mDn+DUqSo+/6CgD8O6Fpm/NXuA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com; spf=pass smtp.mailfrom=linux.microsoft.com; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b=I0IIYF7n; arc=none smtp.client-ip=13.77.154.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="I0IIYF7n" Received: from mrdev.corp.microsoft.com (unknown [13.88.17.9]) by linux.microsoft.com (Postfix) with ESMTPSA id 42CED20B7166; Mon, 11 May 2026 19:03:25 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 42CED20B7166 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1778551406; bh=yuGixt0awDexRy+9+alMff9Qjikz5NAcYVaGls9X8wU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=I0IIYF7ntphGCElNlEKFw9xWXzJMyDwZpLbG8CpaqExl8xhO8TICDV8ytz7AuWcFD u3tqX8k5zXoCQHkpZ98sC3N5PSZo1bqO9VlzqvuGa629tFAhviO+6d8ZggchNsF0A5 R5BMMP1UeVJjj4Rd6nGqKedAlqZMVntHeM1M/be4= From: Mukesh R To: hpa@zytor.com, robin.murphy@arm.com, robh@kernel.org, wei.liu@kernel.org, mrathor@linux.microsoft.com, mhklinux@outlook.com, muislam@microsoft.com, namjain@linux.microsoft.com, magnuskulke@linux.microsoft.com, anbelski@linux.microsoft.com, linux-kernel@vger.kernel.org, linux-hyperv@vger.kernel.org, iommu@lists.linux.dev, linux-pci@vger.kernel.org, linux-arch@vger.kernel.org Cc: kys@microsoft.com, haiyangz@microsoft.com, decui@microsoft.com, longli@microsoft.com, tglx@kernel.org, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, joro@8bytes.org, will@kernel.org, lpieralisi@kernel.org, kwilczynski@kernel.org, bhelgaas@google.com, arnd@arndb.de, jacob.pan@linux.microsoft.com Subject: [PATCH V3 08/11] PCI: hv: VMBus and PCI device IDs for PCI passthru Date: Mon, 11 May 2026 19:02:56 -0700 Message-ID: <20260512020259.1678627-9-mrathor@linux.microsoft.com> X-Mailer: git-send-email 2.51.2.vfs.0.1 In-Reply-To: <20260512020259.1678627-1-mrathor@linux.microsoft.com> References: <20260512020259.1678627-1-mrathor@linux.microsoft.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" On Hyper-V, most hypercalls related to PCI passthru to map/unmap regions, interrupts, etc need a device ID as a parameter. This device ID refers to that specific device during the lifetime of passthru. An L1VH VM only contains VMBus based devices. A device ID for a VMBus device is slightly different in that it uses the hv_pcibus_device info for building it to make sure it matches exactly what the hypervisor expects. This VMBus based device ID is needed when attaching devices in an L1VH based guest VM. Add a function to build and export it. Before building it, a check is done to make sure the device is a valid VMBus device. In remaining cases, PCI device ID is used. So, also make PCI device ID build function hv_build_devid_type_pci() public. Signed-off-by: Mukesh R Reviewed-by: Souradeep Chakrabarti Reviewed-by: Souradeep Chakrabarti --- arch/x86/hyperv/irqdomain.c | 9 +++++---- arch/x86/include/asm/mshyperv.h | 6 ++++++ drivers/pci/controller/pci-hyperv.c | 24 ++++++++++++++++++++++++ include/asm-generic/mshyperv.h | 11 +++++++++++ 4 files changed, 46 insertions(+), 4 deletions(-) diff --git a/arch/x86/hyperv/irqdomain.c b/arch/x86/hyperv/irqdomain.c index b3ad50a874dc..8780573a4332 100644 --- a/arch/x86/hyperv/irqdomain.c +++ b/arch/x86/hyperv/irqdomain.c @@ -112,7 +112,7 @@ static int get_rid_cb(struct pci_dev *pdev, u16 alias, = void *data) return 0; } =20 -static union hv_device_id hv_build_devid_type_pci(struct pci_dev *pdev) +u64 hv_build_devid_type_pci(struct pci_dev *pdev) { int pos; union hv_device_id hv_devid; @@ -172,8 +172,9 @@ static union hv_device_id hv_build_devid_type_pci(struc= t pci_dev *pdev) } =20 out: - return hv_devid; + return hv_devid.as_uint64; } +EXPORT_SYMBOL_GPL(hv_build_devid_type_pci); =20 /* * hv_map_msi_interrupt() - Map the MSI IRQ in the hypervisor. @@ -196,7 +197,7 @@ int hv_map_msi_interrupt(struct irq_data *data, =20 msidesc =3D irq_data_get_msi_desc(data); pdev =3D msi_desc_to_pci_dev(msidesc); - hv_devid =3D hv_build_devid_type_pci(pdev); + hv_devid.as_uint64 =3D hv_build_devid_type_pci(pdev); cpu =3D cpumask_first(irq_data_get_effective_affinity_mask(data)); =20 return hv_map_interrupt(hv_devid, false, cpu, cfg->vector, @@ -271,7 +272,7 @@ static int hv_unmap_msi_interrupt(struct pci_dev *pdev, { union hv_device_id hv_devid; =20 - hv_devid =3D hv_build_devid_type_pci(pdev); + hv_devid.as_uint64 =3D hv_build_devid_type_pci(pdev); return hv_unmap_interrupt(hv_devid.as_uint64, irq_entry); } =20 diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyper= v.h index f64393e853ee..2ef34001f8d3 100644 --- a/arch/x86/include/asm/mshyperv.h +++ b/arch/x86/include/asm/mshyperv.h @@ -248,6 +248,12 @@ void hv_crash_asm_end(void); static inline void hv_root_crash_init(void) {} #endif /* CONFIG_MSHV_ROOT && CONFIG_CRASH_DUMP */ =20 +#if IS_ENABLED(CONFIG_HYPERV_IOMMU) +u64 hv_build_devid_type_pci(struct pci_dev *pdev); +#else +static inline u64 hv_build_devid_type_pci(struct pci_dev *pdev) { return 0= ; } +#endif /* IS_ENABLED(CONFIG_HYPERV_IOMMU) */ + #else /* CONFIG_HYPERV */ static inline void hyperv_init(void) {} static inline void hyperv_setup_mmu_ops(void) {} diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/p= ci-hyperv.c index cfc8fa403dad..50d793ca8f31 100644 --- a/drivers/pci/controller/pci-hyperv.c +++ b/drivers/pci/controller/pci-hyperv.c @@ -573,6 +573,7 @@ struct hv_pci_compl { }; =20 static void hv_pci_onchannelcallback(void *context); +static bool hv_vmbus_pci_device(struct pci_bus *pbus); =20 #ifdef CONFIG_X86 #define DELIVERY_MODE APIC_DELIVERY_MODE_FIXED @@ -1005,6 +1006,24 @@ static struct irq_domain *hv_pci_get_root_domain(voi= d) static void hv_arch_irq_unmask(struct irq_data *data) { } #endif /* CONFIG_ARM64 */ =20 +u64 hv_pci_vmbus_device_id(struct pci_dev *pdev) +{ + struct hv_pcibus_device *hbus; + struct pci_bus *pbus =3D pdev->bus; + + if (!hv_vmbus_pci_device(pbus)) + return 0; + + hbus =3D container_of(pbus->sysdata, struct hv_pcibus_device, sysdata); + + return (hbus->hdev->dev_instance.b[5] << 24) | + (hbus->hdev->dev_instance.b[4] << 16) | + (hbus->hdev->dev_instance.b[7] << 8) | + (hbus->hdev->dev_instance.b[6] & 0xf8) | + PCI_FUNC(pdev->devfn); +} +EXPORT_SYMBOL_GPL(hv_pci_vmbus_device_id); + /** * hv_pci_generic_compl() - Invoked for a completion packet * @context: Set up by the sender of the packet. @@ -1403,6 +1422,11 @@ static struct pci_ops hv_pcifront_ops =3D { .write =3D hv_pcifront_write_config, }; =20 +static bool hv_vmbus_pci_device(struct pci_bus *pbus) +{ + return pbus->ops =3D=3D &hv_pcifront_ops; +} + /* * Paravirtual backchannel * diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h index e8cbc4e3f7ad..25ac7ca0fd8b 100644 --- a/include/asm-generic/mshyperv.h +++ b/include/asm-generic/mshyperv.h @@ -204,6 +204,9 @@ extern u64 (*hv_read_reference_counter)(void); /* Sentinel value for an uninitialized entry in hv_vp_index array */ #define VP_INVAL U32_MAX =20 +/* Forward declarations */ +struct pci_dev; + int __init hv_common_init(void); void __init hv_get_partition_id(void); void __init hv_common_free(void); @@ -316,6 +319,14 @@ void hv_para_set_synic_register(unsigned int reg, u64 = val); void hyperv_cleanup(void); bool hv_query_ext_cap(u64 cap_query); void hv_setup_dma_ops(struct device *dev, bool coherent); + +#if IS_ENABLED(CONFIG_PCI_HYPERV) +u64 hv_pci_vmbus_device_id(struct pci_dev *pdev); +#else +static inline u64 hv_pci_vmbus_device_id(struct pci_dev *pdev) +{ return 0; } +#endif /* IS_ENABLED(CONFIG_PCI_HYPERV) */ + #else /* CONFIG_HYPERV */ static inline void hv_identify_partition_type(void) {} static inline bool hv_is_hyperv_initialized(void) { return false; } --=20 2.51.2.vfs.0.1 From nobody Fri Jun 12 22:47:19 2026 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id C5D972DE702; Tue, 12 May 2026 02:03:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=13.77.154.182 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778551427; cv=none; b=TuFPbuchteumaYIZNCFsewFPVCvYnfc7B+qPEqGL1edYk9YjrnuV7L2tXvRM/kIfKzAgNILndM471Jqxp4sF9vQID67LuUSzRdZTddtGGsJJwC8BYgWo6bgohlJJ+0sTPFR5Y8EvwXj5R3tobTvzA6nJSebA/sqaWXUZm9fiopc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778551427; c=relaxed/simple; bh=zn9xYP0EhyeM5HhYUENB17cLkULp5NxKbzD+RPY9Q0Q=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=rxHCCbSz1B4g42wGSAcQV50MohQ26/eRo4eC8pbm9+rCwYBeapTWq006xW3nZH76csbweSe4BOm9LVzdVAQ8kSGBnMH1bfl+SCIBnW3+tVopjY2gt3QVcDQCxnqCIKtphhhLMQGiTnugQf/+C/7dQ7HPE3C9gaprMVK7byfzEhw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com; spf=pass smtp.mailfrom=linux.microsoft.com; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b=Dnr4U6ux; arc=none smtp.client-ip=13.77.154.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="Dnr4U6ux" Received: from mrdev.corp.microsoft.com (unknown [13.88.17.9]) by linux.microsoft.com (Postfix) with ESMTPSA id B829320B7167; Mon, 11 May 2026 19:03:26 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com B829320B7167 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1778551407; bh=NSAOwsmuBuJnkgf4l8eHX8DiRuMVPP8DEWQw3lR1mtg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Dnr4U6uxNJnc8mUiHMlWb/1f7YWiI4zzPN9EFXsSxap+utcZhjBBLwGVzS1Z7uIva OkMm+AKJEQrcGhJftNpmKouq9BZm/0yNLpvwHiMXO4JjVp6gGbw2po2RdUPolFnWfS Gxxye1TDnfV2n0m8BbrR52HSq8rYouGItZ3TuW0Y= From: Mukesh R To: hpa@zytor.com, robin.murphy@arm.com, robh@kernel.org, wei.liu@kernel.org, mrathor@linux.microsoft.com, mhklinux@outlook.com, muislam@microsoft.com, namjain@linux.microsoft.com, magnuskulke@linux.microsoft.com, anbelski@linux.microsoft.com, linux-kernel@vger.kernel.org, linux-hyperv@vger.kernel.org, iommu@lists.linux.dev, linux-pci@vger.kernel.org, linux-arch@vger.kernel.org Cc: kys@microsoft.com, haiyangz@microsoft.com, decui@microsoft.com, longli@microsoft.com, tglx@kernel.org, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, joro@8bytes.org, will@kernel.org, lpieralisi@kernel.org, kwilczynski@kernel.org, bhelgaas@google.com, arnd@arndb.de, jacob.pan@linux.microsoft.com Subject: [PATCH V3 09/11] x86/hyperv: Implement Hyper-V virtual IOMMU Date: Mon, 11 May 2026 19:02:57 -0700 Message-ID: <20260512020259.1678627-10-mrathor@linux.microsoft.com> X-Mailer: git-send-email 2.51.2.vfs.0.1 In-Reply-To: <20260512020259.1678627-1-mrathor@linux.microsoft.com> References: <20260512020259.1678627-1-mrathor@linux.microsoft.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Add a new file to implement management of device domains, mapping and unmapping of IOMMU memory, and other iommu_ops to fit within the VFIO framework for PCI passthru on Hyper-V running Linux as baremetal root or L1VH root. This also implements direct attach mechanism (see below), a special feature of Hyper-V for PCI passthru, and it is also made to work within the VFIO framework. At a high level, during boot the hypervisor creates a default identity domain and attaches all devices to it. This nicely maps to Linux IOMMU subsystem IOMMU_DOMAIN_IDENTITY domain. As a result, Linux does not need to explicitly ask Hyper-V to attach devices and do maps/unmaps during boot. As mentioned previously, Hyper-V supports two ways to do PCI passthru: 1. Device Domain (aka Domain Attach): root must create a device domain in the hypervisor, and do map/unmap hypercalls for mapping and unmapping guest RAM for DMA. All hypervisor communications use device ID of type PCI for identifying and referencing the device. 2. Direct Attach: the hypervisor will simply use the guest's HW page table for mappings, thus the root need not map/unmap guest memory for DMA. As such, direct attach passthru setup during guest boot is extremely fast. A direct attached device must always be referenced via logical device ID and not via the PCI device ID. At present, L1VH root only supports direct attaches. Also direct attach is default in non-L1VH cases because there are some significant performance issues with domain attach implementations currently for guests with higher RAM (say more than 8GB), and that unfortunately cannot be addressed in the short term. Co-developed-by: Wei Liu Signed-off-by: Wei Liu Signed-off-by: Mukesh R --- MAINTAINERS | 1 + arch/x86/kernel/pci-dma.c | 2 + drivers/iommu/Kconfig | 5 +- drivers/iommu/Makefile | 1 + drivers/iommu/hyperv-iommu-root.c | 918 ++++++++++++++++++++++++++++++ include/asm-generic/mshyperv.h | 17 + include/linux/hyperv.h | 6 + 7 files changed, 947 insertions(+), 3 deletions(-) create mode 100644 drivers/iommu/hyperv-iommu-root.c diff --git a/MAINTAINERS b/MAINTAINERS index f803a6a38fee..8ae040b89a56 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -11914,6 +11914,7 @@ F: drivers/clocksource/hyperv_timer.c F: drivers/hid/hid-hyperv.c F: drivers/hv/ F: drivers/input/serio/hyperv-keyboard.c +F: drivers/iommu/hyperv-iommu-root.c F: drivers/iommu/hyperv-irq.c F: drivers/net/ethernet/microsoft/ F: drivers/net/hyperv/ diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c index 6267363e0189..cfeee6505e17 100644 --- a/arch/x86/kernel/pci-dma.c +++ b/arch/x86/kernel/pci-dma.c @@ -8,6 +8,7 @@ #include #include #include +#include =20 #include #include @@ -105,6 +106,7 @@ void __init pci_iommu_alloc(void) gart_iommu_hole_init(); amd_iommu_detect(); detect_intel_iommu(); + hv_iommu_detect(); swiotlb_init(x86_swiotlb_enable, x86_swiotlb_flags); } =20 diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig index f86262b11416..7909cf4373a6 100644 --- a/drivers/iommu/Kconfig +++ b/drivers/iommu/Kconfig @@ -352,13 +352,12 @@ config MTK_IOMMU_V1 if unsure, say N here. =20 config HYPERV_IOMMU - bool "Hyper-V IRQ Handling" + bool "Hyper-V IOMMU Unit" depends on HYPERV && X86 select IOMMU_API default HYPERV help - Stub IOMMU driver to handle IRQs to support Hyper-V Linux - guest and root partitions. + Hyper-V pseudo IOMMU unit. =20 config VIRTIO_IOMMU tristate "Virtio IOMMU driver" diff --git a/drivers/iommu/Makefile b/drivers/iommu/Makefile index 335ea77cced6..296fbc6ca829 100644 --- a/drivers/iommu/Makefile +++ b/drivers/iommu/Makefile @@ -31,6 +31,7 @@ obj-$(CONFIG_EXYNOS_IOMMU) +=3D exynos-iommu.o obj-$(CONFIG_FSL_PAMU) +=3D fsl_pamu.o fsl_pamu_domain.o obj-$(CONFIG_S390_IOMMU) +=3D s390-iommu.o obj-$(CONFIG_HYPERV) +=3D hyperv-irq.o +obj-$(CONFIG_HYPERV_IOMMU) +=3D hyperv-iommu-root.o obj-$(CONFIG_VIRTIO_IOMMU) +=3D virtio-iommu.o obj-$(CONFIG_IOMMU_SVA) +=3D iommu-sva.o obj-$(CONFIG_IOMMU_IOPF) +=3D io-pgfault.o diff --git a/drivers/iommu/hyperv-iommu-root.c b/drivers/iommu/hyperv-iommu= -root.c new file mode 100644 index 000000000000..a2e0f6cc78e6 --- /dev/null +++ b/drivers/iommu/hyperv-iommu-root.c @@ -0,0 +1,918 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Hyper-V root vIOMMU driver. + * Copyright (C) 2026, Microsoft, Inc. + */ + +#include +#include +#include +#include +#include "dma-iommu.h" +#include +#include + +/* We will not claim these PCI devices, eg hypervisor needs it for debugge= r */ +static char *pci_devs_to_skip; +static int __init hv_iommu_setup_skip(char *str) +{ + pci_devs_to_skip =3D str; + + return 0; +} +/* hv_iommu_skip=3D(SSSS:BB:DD.F)(SSSS:BB:DD.F) */ +__setup("hv_iommu_skip=3D", hv_iommu_setup_skip); + +bool hv_no_attdev; /* disable direct device attach for passthru */ +EXPORT_SYMBOL_GPL(hv_no_attdev); +static int __init setup_hv_no_attdev(char *str) +{ + hv_no_attdev =3D true; + return 0; +} +__setup("hv_no_attdev", setup_hv_no_attdev); + +/* Iommu device that we export to the world. HyperV supports max of one */ +static struct iommu_device hv_virt_iommu; + +struct hv_domain { + struct iommu_domain iommu_dom; + u32 domid_num; /* as opposed to domain_id.type */ + bool attached_dom; /* is this direct attached dom? */ + u64 partid; /* partition id */ + spinlock_t mappings_lock; /* protects mappings_tree */ + struct rb_root_cached mappings_tree; /* iova to pa lookup tree */ +}; + +#define to_hv_domain(d) container_of(d, struct hv_domain, iommu_dom) + +struct hv_iommu_mapping { + phys_addr_t paddr; + struct interval_tree_node iova; + u32 flags; +}; + +/* + * By default, during boot the hypervisor creates one Stage 2 (S2) default + * domain. Stage 2 means that the page table is controlled by the hypervis= or. + * It has two types: + * S2 default: access to entire root partition memory. This for us easily + * maps to IOMMU_DOMAIN_IDENTITY in the iommu subsystem, and + * is called HV_DEVICE_DOMAIN_ID_S2_DEFAULT in the hypervisor. + * S2 NULL: Blocks everything except RMRR + * + * Device Management: + * There are two ways to manage device attaches to domains: + * 1. Domain Attach: A device domain is created in the hypervisor, the + * device is attached to this domain, and then memory + * ranges are mapped in the map callbacks. + * 2. Direct Attach: No need to create a domain in the hypervisor for = direct + * attached devices. A hypercall is made to tell the + * hypervisor to attach the device to a guest. There is + * no need for explicit memory mappings because the + * hypervisor will just use the guest HW page table. + * + * Since a direct attach is much faster, it is the default. This can be + * changed via hv_no_attdev. + * + * L1VH: hypervisor only supports direct attach. Also, there is no S2 defa= ult + * in the hypervisor, so no explicit attach to S2 needed. + */ + +/* + * Create dummy domains to correspond to hypervisor prebuilt default ident= ity + * and null domains (dummy because we do not make hypercalls to create the= m). + */ +static struct hv_domain hv_def_identity_dom; +static struct hv_domain hv_null_dom; + +static bool hv_special_domain(struct hv_domain *hvdom) +{ + return hvdom =3D=3D &hv_def_identity_dom || hvdom =3D=3D &hv_null_dom; +} + +struct iommu_domain_geometry default_geometry =3D (struct iommu_domain_geo= metry) { + .aperture_start =3D 0, + .aperture_end =3D -1UL, + .force_aperture =3D true, +}; + +#define HV_IOMMU_PGSIZES SZ_4K /* for now, to be enhanced */ + +static u32 unique_id; /* unique numeric id of a new domain */ + +static void hv_iommu_detach_dev(struct hv_domain *hvdom, struct device *de= v); +static size_t hv_iommu_unmap_pages(struct iommu_domain *immdom, ulong iova, + size_t pgsize, size_t pgcount, + struct iommu_iotlb_gather *gather); + +/* + * If the current thread is a VMM thread, return the partition id of the V= M it + * is managing, else return HV_PARTITION_ID_INVALID. + */ +u64 hv_get_current_partid(void) +{ + u64 (*fn)(void); + u64 ptid; + + fn =3D symbol_get(mshv_current_partid); + if (!fn) + return HV_PARTITION_ID_INVALID; + + ptid =3D fn(); + symbol_put(mshv_current_partid); + + return ptid; +} +EXPORT_SYMBOL_GPL(hv_get_current_partid); + +/* If this is a VMM thread, then this domain is for a guest vm */ +static bool hv_curr_thread_is_vmm(void) +{ + return hv_get_current_partid() !=3D HV_PARTITION_ID_INVALID; +} + +/* As opposed to some host app like SPDK etc... */ +static bool hv_dom_owner_is_vmm(struct hv_domain *hvdom) +{ + return hvdom && hvdom->partid !=3D HV_PARTITION_ID_INVALID; +} + +static bool hv_iommu_capable(struct device *dev, enum iommu_cap cap) +{ + switch (cap) { + case IOMMU_CAP_CACHE_COHERENCY: + return true; + default: + return false; + } +} + +/* + * Check if given pci device is a direct attached device. Caller must have + * verified pdev is a valid pci device. + */ +bool hv_pcidev_is_attached_dev(struct pci_dev *pdev) +{ + struct iommu_domain *iommu_domain; + struct hv_domain *hvdom; + struct device *dev =3D &pdev->dev; + + iommu_domain =3D iommu_get_domain_for_dev(dev); + if (iommu_domain) { + hvdom =3D to_hv_domain(iommu_domain); + return hvdom->attached_dom; + } + + return false; +} +EXPORT_SYMBOL_GPL(hv_pcidev_is_attached_dev); + +bool hv_pcidev_is_pthru_dev(struct pci_dev *pdev) +{ + struct device *dev =3D &pdev->dev; + struct hv_domain *hvdom =3D dev_iommu_priv_get(dev); + + if (hvdom && !hv_special_domain(hvdom)) + return true; + + return false; +} +EXPORT_SYMBOL_GPL(hv_pcidev_is_pthru_dev); + +/* Build device id for direct attached devices */ +static u64 hv_build_devid_type_logical(struct pci_dev *pdev) +{ + hv_pci_segment segment; + union hv_device_id hv_devid; + union hv_pci_bdf bdf =3D {.as_uint16 =3D 0}; + u32 rid =3D PCI_DEVID(pdev->bus->number, pdev->devfn); + + segment =3D pci_domain_nr(pdev->bus); + bdf.bus =3D PCI_BUS_NUM(rid); + bdf.device =3D PCI_SLOT(rid); + bdf.function =3D PCI_FUNC(rid); + + hv_devid.as_uint64 =3D 0; + hv_devid.device_type =3D HV_DEVICE_TYPE_LOGICAL; + hv_devid.logical.id =3D (u64)segment << 16 | bdf.as_uint16; + + return hv_devid.as_uint64; +} + +u64 hv_build_devid_oftype(struct pci_dev *pdev, enum hv_device_type type) +{ + if (type =3D=3D HV_DEVICE_TYPE_LOGICAL) { + if (hv_l1vh_partition()) + return hv_pci_vmbus_device_id(pdev); + else + return hv_build_devid_type_logical(pdev); + } else if (type =3D=3D HV_DEVICE_TYPE_PCI) +#ifdef CONFIG_X86 + return hv_build_devid_type_pci(pdev); +#else + return 0; +#endif + return 0; +} +EXPORT_SYMBOL_GPL(hv_build_devid_oftype); + +/* Create a new device domain in the hypervisor */ +static int hv_iommu_create_hyp_devdom(struct hv_domain *hvdom) +{ + u64 status; + struct hv_input_device_domain *ddp; + struct hv_input_create_device_domain *input; + unsigned long flags; + + local_irq_save(flags); + input =3D *this_cpu_ptr(hyperv_pcpu_input_arg); + memset(input, 0, sizeof(*input)); + + ddp =3D &input->device_domain; + ddp->partition_id =3D HV_PARTITION_ID_SELF; + ddp->domain_id.type =3D HV_DEVICE_DOMAIN_TYPE_S2; + ddp->domain_id.id =3D hvdom->domid_num; + + input->create_device_domain_flags.forward_progress_required =3D 1; + input->create_device_domain_flags.inherit_owning_vtl =3D 0; + + status =3D hv_do_hypercall(HVCALL_CREATE_DEVICE_DOMAIN, input, NULL); + + local_irq_restore(flags); + + if (!hv_result_success(status)) + hv_status_err(status, "\n"); + + return hv_result_to_errno(status); +} + +static struct iommu_domain *hv_iommu_domain_alloc_paging(struct device *de= v) +{ + struct hv_domain *hvdom; + int rc; + + if (hv_l1vh_partition() && !hv_curr_thread_is_vmm()) { + pr_err("Hyper-V: l1vh iommu does not support host devices\n"); + return NULL; + } + + hvdom =3D kzalloc(sizeof(struct hv_domain), GFP_KERNEL); + if (hvdom =3D=3D NULL) + return NULL; + + spin_lock_init(&hvdom->mappings_lock); + hvdom->mappings_tree =3D RB_ROOT_CACHED; + + /* Called under iommu group mutex, so single threaded */ + if (++unique_id =3D=3D HV_DEVICE_DOMAIN_ID_S2_NULL) /* ie, UINTMAX */ + goto out_err; + + hvdom->domid_num =3D unique_id; + hvdom->partid =3D hv_get_current_partid(); + hvdom->iommu_dom.geometry =3D default_geometry; + hvdom->iommu_dom.pgsize_bitmap =3D HV_IOMMU_PGSIZES; + + /* For guests, by default we do direct attaches, so no domain in hyp */ + if (hv_dom_owner_is_vmm(hvdom) && !hv_no_attdev) + hvdom->attached_dom =3D true; + else { + rc =3D hv_iommu_create_hyp_devdom(hvdom); + if (rc) + goto out_err; + } + + return &hvdom->iommu_dom; + +out_err: + unique_id--; + kfree(hvdom); + return NULL; +} + +static void hv_iommu_domain_free(struct iommu_domain *immdom) +{ + struct hv_domain *hvdom =3D to_hv_domain(immdom); + unsigned long flags; + u64 status; + struct hv_input_delete_device_domain *input; + + if (hv_special_domain(hvdom)) + return; + + if (!hv_dom_owner_is_vmm(hvdom) || hv_no_attdev) { + struct hv_input_device_domain *ddp; + + local_irq_save(flags); + input =3D *this_cpu_ptr(hyperv_pcpu_input_arg); + ddp =3D &input->device_domain; + memset(input, 0, sizeof(*input)); + + ddp->partition_id =3D HV_PARTITION_ID_SELF; + ddp->domain_id.type =3D HV_DEVICE_DOMAIN_TYPE_S2; + ddp->domain_id.id =3D hvdom->domid_num; + + status =3D hv_do_hypercall(HVCALL_DELETE_DEVICE_DOMAIN, input, + NULL); + local_irq_restore(flags); + + if (!hv_result_success(status)) + hv_status_err(status, "\n"); + } + + kfree(hvdom); +} + +/* + * Attach a device to the default domain, or the null domain, or to a doma= in + * previously created in the hypervisor. + */ +static int hv_iommu_att_dev2dom(struct hv_domain *hvdom, struct pci_dev *p= dev) +{ + unsigned long flags; + u64 status; + enum hv_device_type dev_type; + struct hv_input_attach_device_domain *input; + + local_irq_save(flags); + input =3D *this_cpu_ptr(hyperv_pcpu_input_arg); + memset(input, 0, sizeof(*input)); + + /* For null domain, hvdom->domid_num =3D=3D HV_DEVICE_DOMAIN_ID_S2_NULL */ + input->device_domain.partition_id =3D HV_PARTITION_ID_SELF; + input->device_domain.domain_id.type =3D HV_DEVICE_DOMAIN_TYPE_S2; + input->device_domain.domain_id.id =3D hvdom->domid_num; + + /* NB: Upon guest shutdown, device is re-attached to the default domain + * without explicit detach. + */ + if (hv_l1vh_partition()) + dev_type =3D HV_DEVICE_TYPE_LOGICAL; + else + dev_type =3D HV_DEVICE_TYPE_PCI; + + input->device_id.as_uint64 =3D hv_build_devid_oftype(pdev, dev_type); + + status =3D hv_do_hypercall(HVCALL_ATTACH_DEVICE_DOMAIN, input, NULL); + local_irq_restore(flags); + + if (!hv_result_success(status)) + hv_status_err(status, "\n"); + + return hv_result_to_errno(status); +} + +/* Caller must have validated that dev is a valid pci dev */ +static int hv_iommu_direct_attach_device(struct pci_dev *pdev, u64 ptid) +{ + struct hv_input_attach_device *input; + u64 status; + int rc; + unsigned long flags; + union hv_device_id host_devid; + enum hv_device_type dev_type; + + if (ptid =3D=3D HV_PARTITION_ID_INVALID) { + pr_err("Hyper-V: Invalid partition id in direct attach\n"); + return -EINVAL; + } + + if (hv_l1vh_partition()) + dev_type =3D HV_DEVICE_TYPE_LOGICAL; + else + dev_type =3D HV_DEVICE_TYPE_PCI; + + host_devid.as_uint64 =3D hv_build_devid_oftype(pdev, dev_type); + + do { + local_irq_save(flags); + input =3D *this_cpu_ptr(hyperv_pcpu_input_arg); + memset(input, 0, sizeof(*input)); + input->partition_id =3D ptid; + input->device_id =3D host_devid; + + /* Hypervisor associates logical_id with this device, and in + * some hypercalls like retarget interrupts, logical_id must be + * used instead of the BDF. It is a required parameter. + */ + input->attdev_flags.logical_id =3D 1; + input->logical_devid =3D + hv_build_devid_oftype(pdev, HV_DEVICE_TYPE_LOGICAL); + + status =3D hv_do_hypercall(HVCALL_ATTACH_DEVICE, input, NULL); + local_irq_restore(flags); + + if (hv_result(status) =3D=3D HV_STATUS_INSUFFICIENT_MEMORY) { + rc =3D hv_call_deposit_pages(NUMA_NO_NODE, ptid, 1); + if (rc) + break; + } + } while (hv_result(status) =3D=3D HV_STATUS_INSUFFICIENT_MEMORY); + + if (!hv_result_success(status)) + hv_status_err(status, "\n"); + + return hv_result_to_errno(status); +} + +/* Attach a device for passthru to guest VMs, host apps like SPDK, etc */ +static int hv_iommu_attach_dev(struct iommu_domain *immdom, struct device = *dev, + struct iommu_domain *old) +{ + struct pci_dev *pdev; + int rc; + struct hv_domain *hvdom_new =3D to_hv_domain(immdom); + struct hv_domain *hvdom_prev =3D to_hv_domain(old); + + /* Only allow PCI devices for now */ + if (!dev_is_pci(dev)) + return -EINVAL; + + pdev =3D to_pci_dev(dev); + + if (hv_l1vh_partition() && !hv_special_domain(hvdom_new) && + !hvdom_new->attached_dom) + return -EINVAL; + + /* VFIO does not do explicit detach calls, hence check first if we need + * to detach first. Also, in case of guest shutdown, it's the VMM + * thread that attaches it back to the hv_def_identity_dom, and + * hvdom_prev will not be null then. It is null during boot. + */ + if (hvdom_prev) + if (!hv_l1vh_partition() || !hv_special_domain(hvdom_prev)) + hv_iommu_detach_dev(hvdom_prev, dev); + + /* l1vh does not have a default S2 domain in the hypervisor */ + if (hv_l1vh_partition() && hv_special_domain(hvdom_new)) { + dev_iommu_priv_set(dev, hvdom_new); /* sets "private" field */ + return 0; + } + + if (hvdom_new->attached_dom) + rc =3D hv_iommu_direct_attach_device(pdev, hvdom_new->partid); + else + rc =3D hv_iommu_att_dev2dom(hvdom_new, pdev); + + if (rc =3D=3D 0) + dev_iommu_priv_set(dev, hvdom_new); /* sets "private" field */ + else + dev_iommu_priv_set(dev, NULL); + + return rc; +} + +static void hv_iommu_det_dev_from_guest(struct pci_dev *pdev, u64 ptid) +{ + struct hv_input_detach_device *input; + u64 status, log_devid; + unsigned long flags; + + log_devid =3D hv_build_devid_oftype(pdev, HV_DEVICE_TYPE_LOGICAL); + + local_irq_save(flags); + input =3D *this_cpu_ptr(hyperv_pcpu_input_arg); + memset(input, 0, sizeof(*input)); + + input->partition_id =3D ptid; + input->logical_devid =3D log_devid; + status =3D hv_do_hypercall(HVCALL_DETACH_DEVICE, input, NULL); + local_irq_restore(flags); + + if (!hv_result_success(status)) + hv_status_err(status, "\n"); +} + +static void hv_iommu_det_dev_from_dom(struct pci_dev *pdev) +{ + u64 status, devid; + unsigned long flags; + struct hv_input_detach_device_domain *input; + + devid =3D hv_build_devid_oftype(pdev, HV_DEVICE_TYPE_PCI); + + local_irq_save(flags); + input =3D *this_cpu_ptr(hyperv_pcpu_input_arg); + memset(input, 0, sizeof(*input)); + + input->partition_id =3D HV_PARTITION_ID_SELF; + input->device_id.as_uint64 =3D devid; + status =3D hv_do_hypercall(HVCALL_DETACH_DEVICE_DOMAIN, input, NULL); + local_irq_restore(flags); + + if (!hv_result_success(status)) + hv_status_err(status, "\n"); +} + +static void hv_iommu_detach_dev(struct hv_domain *hvdom, struct device *de= v) +{ + struct pci_dev *pdev; + + /* See the attach function, only PCI devices for now */ + if (!dev_is_pci(dev)) + return; + + pdev =3D to_pci_dev(dev); + + if (hvdom->attached_dom) + hv_iommu_det_dev_from_guest(pdev, hvdom->partid); + + /* Do not clear attached_dom, hv_iommu_unmap_pages happens + * next. + */ + else + hv_iommu_det_dev_from_dom(pdev); +} + +static int hv_iommu_add_tree_mapping(struct hv_domain *hvdom, + unsigned long iova, phys_addr_t paddr, + size_t size, u32 flags) +{ + unsigned long irqflags; + struct hv_iommu_mapping *mapping; + + mapping =3D kzalloc(sizeof(*mapping), GFP_ATOMIC); + if (!mapping) + return -ENOMEM; + + mapping->paddr =3D paddr; + mapping->iova.start =3D iova; + mapping->iova.last =3D iova + size - 1; + mapping->flags =3D flags; + + spin_lock_irqsave(&hvdom->mappings_lock, irqflags); + interval_tree_insert(&mapping->iova, &hvdom->mappings_tree); + spin_unlock_irqrestore(&hvdom->mappings_lock, irqflags); + + return 0; +} + +static size_t hv_iommu_del_tree_mappings(struct hv_domain *hvdom, + unsigned long iova, size_t size) +{ + unsigned long flags; + size_t unmapped =3D 0; + unsigned long last =3D iova + size - 1; + struct hv_iommu_mapping *mapping =3D NULL; + struct interval_tree_node *node, *next; + + spin_lock_irqsave(&hvdom->mappings_lock, flags); + next =3D interval_tree_iter_first(&hvdom->mappings_tree, iova, last); + while (next) { + node =3D next; + mapping =3D container_of(node, struct hv_iommu_mapping, iova); + next =3D interval_tree_iter_next(node, iova, last); + + /* Trying to split a mapping? Not supported for now. */ + if (mapping->iova.start < iova) + break; + + unmapped +=3D mapping->iova.last - mapping->iova.start + 1; + + interval_tree_remove(node, &hvdom->mappings_tree); + kfree(mapping); + } + spin_unlock_irqrestore(&hvdom->mappings_lock, flags); + + return unmapped; +} + +/* Return: must return exact status from the hypercall without changes */ +static u64 hv_iommu_map_pgs(struct hv_domain *hvdom, + unsigned long iova, phys_addr_t paddr, + unsigned long npages, u32 map_flags) +{ + u64 status; + int i; + struct hv_input_map_device_gpa_pages *input; + unsigned long flags, pfn; + + local_irq_save(flags); + input =3D *this_cpu_ptr(hyperv_pcpu_input_arg); + memset(input, 0, sizeof(*input)); + + input->device_domain.partition_id =3D HV_PARTITION_ID_SELF; + input->device_domain.domain_id.type =3D HV_DEVICE_DOMAIN_TYPE_S2; + input->device_domain.domain_id.id =3D hvdom->domid_num; + input->map_flags =3D map_flags; + input->target_device_va_base =3D iova; + + pfn =3D paddr >> HV_HYP_PAGE_SHIFT; + for (i =3D 0; i < npages; i++, pfn++) + input->gpa_page_list[i] =3D pfn; + + status =3D hv_do_rep_hypercall(HVCALL_MAP_DEVICE_GPA_PAGES, npages, 0, + input, NULL); + + local_irq_restore(flags); + return status; +} + +#define HV_MAP_DEVICE_GPA_BATCH_SIZE \ + ((HV_HYP_PAGE_SIZE - sizeof(struct hv_input_map_device_gpa_pages)) \ + / sizeof(u64)) + +/* + * The core VFIO code loops over memory ranges calling this function with = the + * largest pgsize from HV_IOMMU_PGSIZES. cond_resched() is in vfio_iommu_m= ap. + */ +static int hv_iommu_map_pages(struct iommu_domain *immdom, ulong iova, + phys_addr_t paddr, size_t pgsize, size_t pgcount, + int prot, gfp_t gfp, size_t *mapped) +{ + u32 map_flags; + int ret; + u64 status; + unsigned long npages, done =3D 0; + struct hv_domain *hvdom =3D to_hv_domain(immdom); + size_t size =3D pgsize * pgcount; + + map_flags =3D HV_MAP_GPA_READABLE; /* required */ + map_flags |=3D prot & IOMMU_WRITE ? HV_MAP_GPA_WRITABLE : 0; + + ret =3D hv_iommu_add_tree_mapping(hvdom, iova, paddr, size, map_flags); + if (ret) + return ret; + + if (hvdom->attached_dom) { + *mapped =3D size; + return 0; + } + + npages =3D size >> HV_HYP_PAGE_SHIFT; + while (done < npages) { + ulong completed, remain =3D npages - done; + + remain =3D min(remain, HV_MAP_DEVICE_GPA_BATCH_SIZE); + + status =3D hv_iommu_map_pgs(hvdom, iova, paddr, remain, + map_flags); + + completed =3D hv_repcomp(status); + done =3D done + completed; + iova =3D iova + (completed << HV_HYP_PAGE_SHIFT); + paddr =3D paddr + (completed << HV_HYP_PAGE_SHIFT); + + if (hv_result(status) =3D=3D HV_STATUS_INSUFFICIENT_MEMORY) { + ret =3D hv_call_deposit_pages(NUMA_NO_NODE, + hv_current_partition_id, + 256); + if (ret) + break; + continue; + } + if (!hv_result_success(status)) + break; + } + + if (!hv_result_success(status)) { + size_t done_size =3D done << HV_HYP_PAGE_SHIFT; + + hv_status_err(status, "pgs:%lx/%lx iova:%lx\n", + done, npages, iova); + /* + * lookup tree has all mappings [0 - size-1]. Below unmap will + * only remove from [0 - done], we need to remove second chunk + * [done+1 - size-1]. + */ + hv_iommu_del_tree_mappings(hvdom, iova, size - done_size); + hv_iommu_unmap_pages(immdom, iova - done_size, HV_HYP_PAGE_SIZE, + done, NULL); + if (mapped) + *mapped =3D 0; + } else + if (mapped) + *mapped =3D size; + + return hv_result_to_errno(status); +} + +static size_t hv_iommu_unmap_pages(struct iommu_domain *immdom, ulong iova, + size_t pgsize, size_t pgcount, + struct iommu_iotlb_gather *gather) +{ + unsigned long flags, npages; + struct hv_input_unmap_device_gpa_pages *input; + u64 status; + struct hv_domain *hvdom =3D to_hv_domain(immdom); + size_t unmapped, size =3D pgsize * pgcount; + + unmapped =3D hv_iommu_del_tree_mappings(hvdom, iova, size); + if (unmapped < size) + pr_err("%s: could not delete all mappings (%lx:%lx/%lx)\n", + __func__, iova, unmapped, size); + + if (hvdom->attached_dom) + return size; + + npages =3D size >> HV_HYP_PAGE_SHIFT; + + local_irq_save(flags); + input =3D *this_cpu_ptr(hyperv_pcpu_input_arg); + memset(input, 0, sizeof(*input)); + + input->device_domain.partition_id =3D HV_PARTITION_ID_SELF; + input->device_domain.domain_id.type =3D HV_DEVICE_DOMAIN_TYPE_S2; + input->device_domain.domain_id.id =3D hvdom->domid_num; + input->target_device_va_base =3D iova; + + status =3D hv_do_rep_hypercall(HVCALL_UNMAP_DEVICE_GPA_PAGES, npages, + 0, input, NULL); + local_irq_restore(flags); + + if (!hv_result_success(status)) + hv_status_err(status, "\n"); + + return unmapped; +} + +static phys_addr_t hv_iommu_iova_to_phys(struct iommu_domain *immdom, + dma_addr_t iova) +{ + unsigned long flags; + struct hv_iommu_mapping *mapping; + struct interval_tree_node *node; + u64 paddr =3D 0; + struct hv_domain *hvdom =3D to_hv_domain(immdom); + + spin_lock_irqsave(&hvdom->mappings_lock, flags); + node =3D interval_tree_iter_first(&hvdom->mappings_tree, iova, iova); + if (node) { + mapping =3D container_of(node, struct hv_iommu_mapping, iova); + paddr =3D mapping->paddr + (iova - mapping->iova.start); + } + spin_unlock_irqrestore(&hvdom->mappings_lock, flags); + + return paddr; +} + +/* + * Currently, hypervisor does not provide list of devices it is using + * dynamically. So use this to allow users to manually specify devices that + * should be skipped. (eg. hypervisor debugger using some network device). + */ +static struct iommu_device *hv_iommu_probe_device(struct device *dev) +{ + if (!dev_is_pci(dev)) + return ERR_PTR(-ENODEV); + + if (pci_devs_to_skip && *pci_devs_to_skip) { + int rc, pos =3D 0; + int parsed; + int segment, bus, slot, func; + struct pci_dev *pdev =3D to_pci_dev(dev); + + do { + parsed =3D 0; + + rc =3D sscanf(pci_devs_to_skip + pos, " (%x:%x:%x.%x) %n", + &segment, &bus, &slot, &func, &parsed); + if (rc) + break; + if (parsed <=3D 0) + break; + + if (pci_domain_nr(pdev->bus) =3D=3D segment && + pdev->bus->number =3D=3D bus && + PCI_SLOT(pdev->devfn) =3D=3D slot && + PCI_FUNC(pdev->devfn) =3D=3D func) { + + dev_info(dev, "skipped by Hyper-V IOMMU\n"); + return ERR_PTR(-ENODEV); + } + pos +=3D parsed; + + } while (pci_devs_to_skip[pos]); + } + + /* Device will be explicitly attached to the default domain, so no need + * to do dev_iommu_priv_set() here. + */ + + return &hv_virt_iommu; +} + +static void hv_iommu_probe_finalize(struct device *dev) +{ + struct iommu_domain *immdom =3D iommu_get_domain_for_dev(dev); + + if (immdom && immdom->type =3D=3D IOMMU_DOMAIN_DMA) + iommu_setup_dma_ops(dev, immdom); + else + set_dma_ops(dev, NULL); +} + +static void hv_iommu_release_device(struct device *dev) +{ + struct hv_domain *hvdom =3D dev_iommu_priv_get(dev); + + /* Need to detach device from device domain if necessary. */ + if (hvdom) + hv_iommu_detach_dev(hvdom, dev); + + dev_iommu_priv_set(dev, NULL); + set_dma_ops(dev, NULL); +} + +static struct iommu_group *hv_iommu_device_group(struct device *dev) +{ + if (dev_is_pci(dev)) + return pci_device_group(dev); + else + return generic_device_group(dev); +} + +static int hv_iommu_def_domain_type(struct device *dev) +{ + /* The hypervisor always creates this by default during boot */ + return IOMMU_DOMAIN_IDENTITY; +} + +static struct iommu_ops hv_iommu_ops =3D { + .capable =3D hv_iommu_capable, + .domain_alloc_paging =3D hv_iommu_domain_alloc_paging, + .probe_device =3D hv_iommu_probe_device, + .probe_finalize =3D hv_iommu_probe_finalize, + .release_device =3D hv_iommu_release_device, + .def_domain_type =3D hv_iommu_def_domain_type, + .device_group =3D hv_iommu_device_group, + .default_domain_ops =3D &(const struct iommu_domain_ops) { + .attach_dev =3D hv_iommu_attach_dev, + .map_pages =3D hv_iommu_map_pages, + .unmap_pages =3D hv_iommu_unmap_pages, + .iova_to_phys =3D hv_iommu_iova_to_phys, + .free =3D hv_iommu_domain_free, + }, + .owner =3D THIS_MODULE, + .identity_domain =3D &hv_def_identity_dom.iommu_dom, + .blocked_domain =3D &hv_null_dom.iommu_dom, +}; + +static const struct iommu_domain_ops hv_special_domain_ops =3D { + .attach_dev =3D hv_iommu_attach_dev, +}; + +static void __init hv_initialize_special_domains(void) +{ + hv_def_identity_dom.iommu_dom.type =3D IOMMU_DOMAIN_IDENTITY; + hv_def_identity_dom.iommu_dom.ops =3D &hv_special_domain_ops; + hv_def_identity_dom.iommu_dom.owner =3D &hv_iommu_ops; + hv_def_identity_dom.iommu_dom.geometry =3D default_geometry; + hv_def_identity_dom.domid_num =3D HV_DEVICE_DOMAIN_ID_S2_DEFAULT; /* 0 */ + + hv_null_dom.iommu_dom.type =3D IOMMU_DOMAIN_BLOCKED; + hv_null_dom.iommu_dom.ops =3D &hv_special_domain_ops; + hv_null_dom.iommu_dom.owner =3D &hv_iommu_ops; + hv_null_dom.iommu_dom.geometry =3D default_geometry; + hv_null_dom.domid_num =3D HV_DEVICE_DOMAIN_ID_S2_NULL; /* INTMAX */ +} + +static int __init hv_iommu_init(void) +{ + int ret; + struct iommu_device *iommup =3D &hv_virt_iommu; + + if (!hv_is_hyperv_initialized()) + return -ENODEV; + + ret =3D iommu_device_sysfs_add(iommup, NULL, NULL, "%s", "hyperv-iommu"); + if (ret) { + pr_err("Hyper-V: iommu_device_sysfs_add failed: %d\n", ret); + return ret; + } + + /* This must come before iommu_device_register because the latter calls + * into the hooks. + */ + hv_initialize_special_domains(); + + ret =3D iommu_device_register(iommup, &hv_iommu_ops, NULL); + if (ret) { + pr_err("Hyper-V: iommu_device_register failed: %d\n", ret); + goto err_sysfs_remove; + } + + pr_info("Hyper-V IOMMU initialized\n"); + + return 0; + +err_sysfs_remove: + iommu_device_sysfs_remove(iommup); + return ret; +} + +void __init hv_iommu_detect(void) +{ + if (no_iommu || iommu_detected) + return; + + /* For l1vh, always expose an iommu unit */ + if (!hv_l1vh_partition()) + if (!(ms_hyperv.misc_features & HV_DEVICE_DOMAIN_AVAILABLE)) + return; + + iommu_detected =3D 1; + x86_init.iommu.iommu_init =3D hv_iommu_init; + + pci_request_acs(); +} diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h index 25ac7ca0fd8b..8d5c610da99a 100644 --- a/include/asm-generic/mshyperv.h +++ b/include/asm-generic/mshyperv.h @@ -327,6 +327,23 @@ static inline u64 hv_pci_vmbus_device_id(struct pci_de= v *pdev) { return 0; } #endif /* IS_ENABLED(CONFIG_PCI_HYPERV) */ =20 +#if IS_ENABLED(CONFIG_HYPERV_IOMMU) +u64 hv_get_current_partid(void); +bool hv_pcidev_is_attached_dev(struct pci_dev *pdev); +bool hv_pcidev_is_pthru_dev(struct pci_dev *pdev); +u64 hv_build_devid_oftype(struct pci_dev *pdev, enum hv_device_type type); +#else +static inline bool hv_pcidev_is_attached_dev(struct pci_dev *pdev) +{ return false; } +static inline bool hv_pcidev_is_pthru_dev(struct pci_dev *pdev) +{ return false; } +static inline u64 hv_build_devid_oftype(struct pci_dev *pdev, + enum hv_device_type type) +{ return 0; } +static inline u64 hv_get_current_partid(void) +{ return HV_PARTITION_ID_INVALID; } +#endif /* IS_ENABLED(CONFIG_HYPERV_IOMMU) */ + #else /* CONFIG_HYPERV */ static inline void hv_identify_partition_type(void) {} static inline bool hv_is_hyperv_initialized(void) { return false; } diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h index 5459e776ec17..6eee1cbf6f23 100644 --- a/include/linux/hyperv.h +++ b/include/linux/hyperv.h @@ -1769,4 +1769,10 @@ static inline unsigned long virt_to_hvpfn(void *addr) #define HVPFN_DOWN(x) ((x) >> HV_HYP_PAGE_SHIFT) #define page_to_hvpfn(page) (page_to_pfn(page) * NR_HV_HYP_PAGES_IN_PAGE) =20 +#ifdef CONFIG_HYPERV_IOMMU +void __init hv_iommu_detect(void); +#else +static inline void hv_iommu_detect(void) { } +#endif /* CONFIG_HYPERV_IOMMU */ + #endif /* _HYPERV_H */ --=20 2.51.2.vfs.0.1 From nobody Fri Jun 12 22:47:19 2026 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 669322DB795; Tue, 12 May 2026 02:03:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=13.77.154.182 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778551419; cv=none; b=W699MS3b1UA15j1SQIAsl398gnEYFfXZX1e/ocqfIyWaHKPJ9IqRP4Hln17zp2uP9wT3qAq1puO/CfUR8uYLAELNSoAUvFHcthjYyKQqvXelVxepK+OvKROWvtLK4tSKKFRcdl8l+JQBtKw+fo72vZ5gvq9IitScOIlt53W17QI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778551419; c=relaxed/simple; bh=3TNU4EMnv17LluIqrnkhvD8xOvL+YdsPt3gnwRHpmUc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=TgbAEBZIa0YSg4kwr/dKxgYS7YTx6/qpaqsThf744eknX8Dn1IbEwzg+L2+eTi4yO74YrwoWBG+nyt076hhvGJ/FLoqFdm0d4Qy8Mx0foWbpOpBW4w13OsZYwa+P3OiLGOIMHP3f2wVt9PtIggeCz9BeK5ssaNeKNG5xxXhMKyk= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com; spf=pass smtp.mailfrom=linux.microsoft.com; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b=mc601FcS; arc=none smtp.client-ip=13.77.154.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="mc601FcS" Received: from mrdev.corp.microsoft.com (unknown [13.88.17.9]) by linux.microsoft.com (Postfix) with ESMTPSA id 0527B20B7169; Mon, 11 May 2026 19:03:32 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 0527B20B7169 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1778551414; bh=84awl3Z2Kbawc6FZaMJAbg5OX/GvsOXiTuFqfIzdbWs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mc601FcSJKcnbNuX0XLhOmQd4Fa+Tr8yZhF7P3o+j5+mHcR/i8/ixj1ybfZQ+XpEY Jvr9POXq0IXP0ILrOGIEpHYLFMV8y+csHK6LaKjv0oZLVDRDc7ihNPa6GWhILMevZV 3pu6UfZOr2UYm099DMv4cqk1kdIbpuOToSXino0Y= From: Mukesh R To: hpa@zytor.com, robin.murphy@arm.com, robh@kernel.org, wei.liu@kernel.org, mrathor@linux.microsoft.com, mhklinux@outlook.com, muislam@microsoft.com, namjain@linux.microsoft.com, magnuskulke@linux.microsoft.com, anbelski@linux.microsoft.com, linux-kernel@vger.kernel.org, linux-hyperv@vger.kernel.org, iommu@lists.linux.dev, linux-pci@vger.kernel.org, linux-arch@vger.kernel.org Cc: kys@microsoft.com, haiyangz@microsoft.com, decui@microsoft.com, longli@microsoft.com, tglx@kernel.org, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, joro@8bytes.org, will@kernel.org, lpieralisi@kernel.org, kwilczynski@kernel.org, bhelgaas@google.com, arnd@arndb.de, jacob.pan@linux.microsoft.com Subject: [PATCH V3 10/11] mshv: Populate mmio mappings for PCI passthru Date: Mon, 11 May 2026 19:02:58 -0700 Message-ID: <20260512020259.1678627-11-mrathor@linux.microsoft.com> X-Mailer: git-send-email 2.51.2.vfs.0.1 In-Reply-To: <20260512020259.1678627-1-mrathor@linux.microsoft.com> References: <20260512020259.1678627-1-mrathor@linux.microsoft.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Upon guest access, in case of missing mmio mapping, the hypervisor generates an unmapped gpa intercept. In this path, lookup the PCI resource pfn for the guest gpa, and ask the hypervisor to map it via hypercall. The PCI resource pfn is maintained by the VFIO driver, and obtained via fixup_user_fault call (similar to KVM). Also, VFIO no longer puts the mmio pfn in vma->vm_pgoff. So, remove code that is using it to map mmio space. It is broken and will cause panic. Signed-off-by: Mukesh R --- drivers/hv/mshv_root_main.c | 113 ++++++++++++++++++++++++++++++------ 1 file changed, 96 insertions(+), 17 deletions(-) diff --git a/drivers/hv/mshv_root_main.c b/drivers/hv/mshv_root_main.c index 6ceb5f608589..a7864463961b 100644 --- a/drivers/hv/mshv_root_main.c +++ b/drivers/hv/mshv_root_main.c @@ -46,6 +46,9 @@ MODULE_DESCRIPTION("Microsoft Hyper-V root partition VMM = interface /dev/mshv"); #define HV_VP_COUNTER_ROOT_DISPATCH_THREAD_BLOCKED 95 #endif =20 +static bool hv_nofull_mmio; /* don't map entire mmio region upon fault */ +module_param(hv_nofull_mmio, bool, 0644); + struct mshv_root mshv_root; =20 enum hv_scheduler_type hv_scheduler_type; @@ -641,6 +644,94 @@ mshv_partition_region_by_gfn_get(struct mshv_partition= *p, u64 gfn) return region; } =20 +/* + * Check if uaddr is for mmio range. If yes, return 0 with mmio_pfn filled= in + * else just return -errno. + */ +static int mshv_chk_get_mmio_start_pfn(u64 uaddr, u64 *mmio_pfnp) +{ + struct vm_area_struct *vma; + bool is_mmio; + struct follow_pfnmap_args pfnmap_args; + int rc =3D -EINVAL; + + mmap_read_lock(current->mm); + vma =3D vma_lookup(current->mm, uaddr); + is_mmio =3D vma ? !!(vma->vm_flags & (VM_IO | VM_PFNMAP)) : 0; + if (!is_mmio) + goto unlock_mmap_out; + + pfnmap_args.vma =3D vma; + pfnmap_args.address =3D uaddr; + + rc =3D follow_pfnmap_start(&pfnmap_args); + if (rc) { + rc =3D fixup_user_fault(current->mm, uaddr, FAULT_FLAG_WRITE, + NULL); + if (rc) + goto unlock_mmap_out; + + rc =3D follow_pfnmap_start(&pfnmap_args); + if (rc) + goto unlock_mmap_out; + } + + *mmio_pfnp =3D pfnmap_args.pfn; + follow_pfnmap_end(&pfnmap_args); + +unlock_mmap_out: + mmap_read_unlock(current->mm); + return rc; +} + +/* + * Check if the unmapped gpa belongs to mmio space. If yes, resolve it. + * + * Returns: True if valid mmio intercept and handled, else false. + */ +static bool mshv_handle_unmapped_gpa(struct mshv_vp *vp) +{ + struct hv_message *hvmsg =3D vp->vp_intercept_msg_page; + u64 gfn, uaddr, mmio_spa, numpgs; + struct mshv_mem_region *rg; + int rc =3D -EINVAL; + struct mshv_partition *pt =3D vp->vp_partition; +#if defined(CONFIG_X86_64) + struct hv_x64_memory_intercept_message *msg =3D + (struct hv_x64_memory_intercept_message *)hvmsg->u.payload; +#elif defined(CONFIG_ARM64) + struct hv_arm64_memory_intercept_message *msg =3D + (struct hv_arm64_memory_intercept_message *)hvmsg->u.payload; +#endif + + gfn =3D msg->guest_physical_address >> HV_HYP_PAGE_SHIFT; + + rg =3D mshv_partition_region_by_gfn_get(pt, gfn); + if (rg =3D=3D NULL) + return false; + if (rg->mreg_type !=3D MSHV_REGION_TYPE_MMIO) + goto put_rg_out; + + uaddr =3D rg->start_uaddr + ((gfn - rg->start_gfn) << HV_HYP_PAGE_SHIFT); + + rc =3D mshv_chk_get_mmio_start_pfn(uaddr, &mmio_spa); + if (rc) + goto put_rg_out; + + if (!hv_nofull_mmio) { /* default case */ + mmio_spa =3D mmio_spa - (gfn - rg->start_gfn); + gfn =3D rg->start_gfn; + numpgs =3D rg->nr_pages; + } else + numpgs =3D 1; + + rc =3D hv_call_map_mmio_pages(pt->pt_id, gfn, mmio_spa, numpgs); + +put_rg_out: + mshv_region_put(rg); + return rc =3D=3D 0; +} + /** * mshv_handle_gpa_intercept - Handle GPA (Guest Physical Address) interce= pts. * @vp: Pointer to the virtual processor structure. @@ -699,6 +790,8 @@ static bool mshv_handle_gpa_intercept(struct mshv_vp *v= p) static bool mshv_vp_handle_intercept(struct mshv_vp *vp) { switch (vp->vp_intercept_msg_page->header.message_type) { + case HVMSG_UNMAPPED_GPA: + return mshv_handle_unmapped_gpa(vp); case HVMSG_GPA_INTERCEPT: return mshv_handle_gpa_intercept(vp); } @@ -1322,16 +1415,8 @@ static int mshv_prepare_pinned_region(struct mshv_me= m_region *region) } =20 /* - * This maps two things: guest RAM and for pci passthru mmio space. - * - * mmio: - * - vfio overloads vm_pgoff to store the mmio start pfn/spa. - * - Two things need to happen for mapping mmio range: - * 1. mapped in the uaddr so VMM can access it. - * 2. mapped in the hwpt (gfn <-> mmio phys addr) so guest can access it. - * - * This function takes care of the second. The first one is managed by v= fio, - * and hence is taken care of via vfio_pci_mmap_fault(). + * This is called for both user ram and mmio space. The mmio space is not + * mapped here, but later during intercept on demand. */ static long mshv_map_user_memory(struct mshv_partition *partition, @@ -1340,7 +1425,6 @@ mshv_map_user_memory(struct mshv_partition *partition, struct mshv_mem_region *region; struct vm_area_struct *vma; bool is_mmio; - ulong mmio_pfn; long ret; =20 if (mem->flags & BIT(MSHV_SET_MEM_BIT_UNMAP) || @@ -1350,7 +1434,6 @@ mshv_map_user_memory(struct mshv_partition *partition, mmap_read_lock(current->mm); vma =3D vma_lookup(current->mm, mem->userspace_addr); is_mmio =3D vma ? !!(vma->vm_flags & (VM_IO | VM_PFNMAP)) : 0; - mmio_pfn =3D is_mmio ? vma->vm_pgoff : 0; mmap_read_unlock(current->mm); =20 if (!vma) @@ -1376,11 +1459,7 @@ mshv_map_user_memory(struct mshv_partition *partitio= n, region->nr_pages, HV_MAP_GPA_NO_ACCESS, NULL); break; - case MSHV_REGION_TYPE_MMIO: - ret =3D hv_call_map_mmio_pages(partition->pt_id, - region->start_gfn, - mmio_pfn, - region->nr_pages); + default: break; } =20 --=20 2.51.2.vfs.0.1 From nobody Fri Jun 12 22:47:19 2026 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 75C682DCF61; Tue, 12 May 2026 02:03:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=13.77.154.182 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778551419; cv=none; b=uEkGBvssj4Tn/aMm6AmujMf57OXhTCusXFRpMm3HgHSSjX1YMjT3zT/cwFjyMl6APD1E6HdWa6cWhgv7NfpBt6vysWR/P74HS2Yc6LVe/snAyU4lEslC//ZJAP09TzoLDCXBjJ6e2MkfhizkvoAxetxPJUu0VoWAijwEtzmVVcw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778551419; c=relaxed/simple; bh=mcU8SYICc38QiN8NqXflQT7TqsEN9UagRERq43TZdyQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=u8auDDBBh4CnAGKCvroGm5irUAAPSqkDOop7q1bzpCfdni6nhm1ldMSI3zv2fWjOWwMoBragODp6t1SQiKo1uRuUF9ZYirsdNhureugGi4rKbS1NggMCxk2JvIw6bOeHc1Kda3UBkEl3PTElUSEFsWQ9rjQPHCqb4K6oWxkbTKE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com; spf=pass smtp.mailfrom=linux.microsoft.com; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b=NTeU0sdY; arc=none smtp.client-ip=13.77.154.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="NTeU0sdY" Received: from mrdev.corp.microsoft.com (unknown [13.88.17.9]) by linux.microsoft.com (Postfix) with ESMTPSA id 2787520B7166; Mon, 11 May 2026 19:03:35 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 2787520B7166 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1778551416; bh=Tzlgjea1nxDXUDjkwgZNQOaBEUR7afZAQnfUGwI6GXc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NTeU0sdYKlCVn4zmKJp/M3HEpo/gh7wqiqVZW2PgndcW0+qWnjqbNv4nNAB31m9N+ u90bRFlOJw9Sx4UEhYVbBqqETioypQGEdjE1b0TqMVaRnTkyl2ZjKGsj9s+HWZT2TR dq9rdJ//JsXBeDXtGK89krk/O+FzLuWvXwoWeYhU= From: Mukesh R To: hpa@zytor.com, robin.murphy@arm.com, robh@kernel.org, wei.liu@kernel.org, mrathor@linux.microsoft.com, mhklinux@outlook.com, muislam@microsoft.com, namjain@linux.microsoft.com, magnuskulke@linux.microsoft.com, anbelski@linux.microsoft.com, linux-kernel@vger.kernel.org, linux-hyperv@vger.kernel.org, iommu@lists.linux.dev, linux-pci@vger.kernel.org, linux-arch@vger.kernel.org Cc: kys@microsoft.com, haiyangz@microsoft.com, decui@microsoft.com, longli@microsoft.com, tglx@kernel.org, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, joro@8bytes.org, will@kernel.org, lpieralisi@kernel.org, kwilczynski@kernel.org, bhelgaas@google.com, arnd@arndb.de, jacob.pan@linux.microsoft.com Subject: [PATCH V3 11/11] mshv: Mark mem regions as non-movable upfront if device passthru Date: Mon, 11 May 2026 19:02:59 -0700 Message-ID: <20260512020259.1678627-12-mrathor@linux.microsoft.com> X-Mailer: git-send-email 2.51.2.vfs.0.1 In-Reply-To: <20260512020259.1678627-1-mrathor@linux.microsoft.com> References: <20260512020259.1678627-1-mrathor@linux.microsoft.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" If a VM is started with device attached, the mem regions must be marked non-movable as the device attach hypercall right away allows the use of SLAT for IOMMU. Marking them non-movable forces mapping of the entire guest RAM in the SLAT at the time of region creation along with the region pinned. Also, because a device could be dynamically attached much later in a VM, create a boot parameter to disable movable pages that users can set if they anticipate such an action. Signed-off-by: Mukesh R --- drivers/hv/mshv_root.h | 1 + drivers/hv/mshv_root_main.c | 15 ++++++++++++++- 2 files changed, 15 insertions(+), 1 deletion(-) diff --git a/drivers/hv/mshv_root.h b/drivers/hv/mshv_root.h index b9880d0bdc4d..d57c26950203 100644 --- a/drivers/hv/mshv_root.h +++ b/drivers/hv/mshv_root.h @@ -141,6 +141,7 @@ struct mshv_partition { pid_t pt_vmm_tgid; bool import_completed; bool pt_initialized; + bool pt_regions_pinned; #if IS_ENABLED(CONFIG_DEBUG_FS) struct dentry *pt_stats_dentry; struct dentry *pt_vp_dentry; diff --git a/drivers/hv/mshv_root_main.c b/drivers/hv/mshv_root_main.c index a7864463961b..ac71534733bd 100644 --- a/drivers/hv/mshv_root_main.c +++ b/drivers/hv/mshv_root_main.c @@ -49,6 +49,10 @@ MODULE_DESCRIPTION("Microsoft Hyper-V root partition VMM= interface /dev/mshv"); static bool hv_nofull_mmio; /* don't map entire mmio region upon fault */ module_param(hv_nofull_mmio, bool, 0644); =20 +static bool hv_no_movbl_pgs; /* disable movable pages completely */ +module_param(hv_no_movbl_pgs, bool, 0644); +MODULE_PARM_DESC(hv_no_movbl_pgs, "If set, don't do movable pages for VMs"= ); + struct mshv_root mshv_root; =20 enum hv_scheduler_type hv_scheduler_type; @@ -1303,6 +1307,12 @@ static void mshv_async_hvcall_handler(void *data, u6= 4 *status) *status =3D partition->async_hypercall_status; } =20 +static bool mshv_do_pt_regions_pinned(struct mshv_partition *pt) +{ + return pt->pt_regions_pinned || mshv_partition_encrypted(pt) || + hv_no_movbl_pgs; +} + /* * NB: caller checks and makes sure mem->size is page aligned * Returns: 0 with regionpp updated on success, or -errno @@ -1333,7 +1343,7 @@ static int mshv_partition_create_region(struct mshv_p= artition *partition, =20 if (is_mmio) rg->mreg_type =3D MSHV_REGION_TYPE_MMIO; - else if (mshv_partition_encrypted(partition) || + else if (mshv_do_pt_regions_pinned(partition) || !mshv_region_movable_init(rg)) rg->mreg_type =3D MSHV_REGION_TYPE_MEM_PINNED; else @@ -1808,6 +1818,9 @@ static long mshv_partition_ioctl_create_device(struct= mshv_partition *partition, if (copy_to_user(uarg, &devargk, sizeof(devargk))) return -EFAULT; /* cleanup in mshv_device_fop_release() */ =20 + /* For now, all regions must be pinned if there is device passthru. */ + partition->pt_regions_pinned =3D true; + return 0; =20 undo_out: --=20 2.51.2.vfs.0.1