From nobody Thu Oct 2 21:57:08 2025 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id D179E3064BA; Wed, 10 Sep 2025 23:14:53 +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=1757546095; cv=none; b=VeAaQUAYDuntwl3MauDk0zmiQXF31xwuuZ4GrFRTSKEOT0xjaO5Mm1o6KmQA1/xVloR1Avnz/Jqas7CetwCYGupjtKltWl1qBbQre8eHvTMv3KfYi6w0//ouXYffUFUJiTMwpxHtpfv7xSnKZ99dTfwdkHVumsLif02/Npw7uO8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757546095; c=relaxed/simple; bh=JKG2hrISRHt0TewSEFAEtrgOmkR+vtp8APLClCnXgmI=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References; b=bsEPqQofEUcN9kxmBOITMthY5R1KvHZzR2RtI3zkkcCT7eU4WKNQiSBMiZyBE0JSNoevNvN+dTJ6xsq3pOEZOPyQ++85dAZ9qg82cJa27gKy8lbE7fNKFe4H8MuU5PZQlsKof34xAKCwG/oigf6V7XhROlmsOslEqUmfbgAsTtQ= 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=AuGqc7Tw; 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="AuGqc7Tw" Received: by linux.microsoft.com (Postfix, from userid 1032) id 9F47A2018E71; Wed, 10 Sep 2025 16:14:53 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 9F47A2018E71 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1757546093; bh=YCh3wgVuB2vh0c+UXuVPwE26nnFHIhu86EFs4zuEOig=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=AuGqc7TwHV3NW9CxbpgutRESHvI6kN3x1xW65SOx0A/hn5jPrkpwmzv3OamnTOdoo wA6GgAX/+hfX1RYiK0SmvYYP06sMZ0wdFXCQz6VNbHXU9C+af/Ijw94la0kaYVsuYX FrIAA2gsG+77I0MHIz4wlspu+pgnJq27qJnHYECA= From: Nuno Das Neves To: linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org, prapal@linux.microsoft.com, easwar.hariharan@linux.microsoft.com, tiala@microsoft.com, anirudh@anirudhrb.com, paekkaladevi@linux.microsoft.com Cc: kys@microsoft.com, haiyangz@microsoft.com, wei.liu@kernel.org, decui@microsoft.com, Nuno Das Neves Subject: [PATCH v2 3/5] mshv: Get the vmm capabilities offered by the hypervisor Date: Wed, 10 Sep 2025 16:14:47 -0700 Message-Id: <1757546089-2002-4-git-send-email-nunodasneves@linux.microsoft.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1757546089-2002-1-git-send-email-nunodasneves@linux.microsoft.com> References: <1757546089-2002-1-git-send-email-nunodasneves@linux.microsoft.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" From: Purna Pavan Chandra Aekkaladevi Some hypervisor APIs are gated by feature bits in the "vmm capabilities" partition property. Store the capabilities on mshv_root module init, using HVCALL_GET_PARTITION_PROPERTY_EX. This is not supported on all hypervisors. In that case, just set the capabilities to 0 and proceed as normal. Signed-off-by: Purna Pavan Chandra Aekkaladevi Signed-off-by: Nuno Das Neves Reviewed-by: Praveen K Paladugu Reviewed-by: Easwar Hariharan Reviewed-by: Tianyu Lan --- drivers/hv/mshv_root.h | 1 + drivers/hv/mshv_root_main.c | 22 ++++++++++++++++++++++ 2 files changed, 23 insertions(+) diff --git a/drivers/hv/mshv_root.h b/drivers/hv/mshv_root.h index 4aeb03bea6b6..0cb1e2589fe1 100644 --- a/drivers/hv/mshv_root.h +++ b/drivers/hv/mshv_root.h @@ -178,6 +178,7 @@ struct mshv_root { struct hv_synic_pages __percpu *synic_pages; spinlock_t pt_ht_lock; DECLARE_HASHTABLE(pt_htable, MSHV_PARTITIONS_HASH_BITS); + struct hv_partition_property_vmm_capabilities vmm_caps; }; =20 /* diff --git a/drivers/hv/mshv_root_main.c b/drivers/hv/mshv_root_main.c index 24df47726363..f7738cefbdf3 100644 --- a/drivers/hv/mshv_root_main.c +++ b/drivers/hv/mshv_root_main.c @@ -2201,6 +2201,26 @@ static int __init mshv_root_partition_init(struct de= vice *dev) return err; } =20 +static void mshv_init_vmm_caps(struct device *dev) +{ + int ret; + + memset(&mshv_root.vmm_caps, 0, sizeof(mshv_root.vmm_caps)); + ret =3D hv_call_get_partition_property_ex(HV_PARTITION_ID_SELF, + HV_PARTITION_PROPERTY_VMM_CAPABILITIES, + 0, &mshv_root.vmm_caps, + sizeof(mshv_root.vmm_caps)); + + /* + * HVCALL_GET_PARTITION_PROPERTY_EX or HV_PARTITION_PROPERTY_VMM_CAPABILI= TIES + * may not be supported. Leave them as 0 in that case. + */ + if (ret) + dev_warn(dev, "Unable to get VMM capabilities\n"); + + dev_dbg(dev, "vmm_caps=3D0x%llx\n", mshv_root.vmm_caps.as_uint64[0]); +} + static int __init mshv_parent_partition_init(void) { int ret; @@ -2253,6 +2273,8 @@ static int __init mshv_parent_partition_init(void) if (ret) goto remove_cpu_state; =20 + mshv_init_vmm_caps(dev); + ret =3D mshv_irqfd_wq_init(); if (ret) goto exit_partition; --=20 2.34.1