From nobody Tue Apr 30 04:57:58 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1507519263174508.983864921194; Sun, 8 Oct 2017 20:21:03 -0700 (PDT) Received: from localhost ([::1]:55882 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1e1Ocj-0000xD-6K for importer@patchew.org; Sun, 08 Oct 2017 23:20:57 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:45168) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1e1Obe-0000ON-Tc for qemu-devel@nongnu.org; Sun, 08 Oct 2017 23:19:52 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1e1Oba-0003ES-Ti for qemu-devel@nongnu.org; Sun, 08 Oct 2017 23:19:50 -0400 Received: from ozlabs.ru ([107.173.13.209]:58180) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1e1Oba-0003Dx-Jo for qemu-devel@nongnu.org; Sun, 08 Oct 2017 23:19:46 -0400 Received: from vpl1.ozlabs.ibm.com (localhost [IPv6:::1]) by ozlabs.ru (Postfix) with ESMTP id 658FF3A60023; Sun, 8 Oct 2017 23:18:28 -0400 (EDT) From: Alexey Kardashevskiy To: qemu-devel@nongnu.org Date: Mon, 9 Oct 2017 14:19:41 +1100 Message-Id: <20171009031941.31916-1-aik@ozlabs.ru> X-Mailer: git-send-email 2.11.0 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [fuzzy] X-Received-From: 107.173.13.209 Subject: [Qemu-devel] [PATCH qemu v2] virtio-pci: Replace modern_as with direct access to modern_bar X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Alexey Kardashevskiy , Paolo Bonzini , David Gibson , "Michael S. Tsirkin" Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" The modern bar is accessed now via yet another address space created just for that purpose and it does not really need FlatView and dispatch tree as it has a single memory region so it is just a waste of memory. Things get even worse when there are dozens or hundreds of virtio-pci devices - since these address spaces are global, changing any of them triggers rebuilding all address spaces. This replaces indirect accesses to the modern BAR with a simple lookup and direct calls to memory_region_dispatch_read/write. This is expected to save lots of memory at boot time after applying: [Qemu-devel] [PULL 00/32] Misc changes for 2017-09-22 Signed-off-by: Alexey Kardashevskiy --- Changes: v2: * replaced assert(mr) with a silent return --- hw/virtio/virtio-pci.h | 17 +++++++----- hw/virtio/virtio-pci.c | 75 +++++++++++++++++++++++++++++-----------------= ---- 2 files changed, 54 insertions(+), 38 deletions(-) diff --git a/hw/virtio/virtio-pci.h b/hw/virtio/virtio-pci.h index 69f5959623..12d3a90686 100644 --- a/hw/virtio/virtio-pci.h +++ b/hw/virtio/virtio-pci.h @@ -155,15 +155,18 @@ typedef struct VirtIOPCIQueue { struct VirtIOPCIProxy { PCIDevice pci_dev; MemoryRegion bar; - VirtIOPCIRegion common; - VirtIOPCIRegion isr; - VirtIOPCIRegion device; - VirtIOPCIRegion notify; - VirtIOPCIRegion notify_pio; + union { + struct { + VirtIOPCIRegion common; + VirtIOPCIRegion isr; + VirtIOPCIRegion device; + VirtIOPCIRegion notify; + VirtIOPCIRegion notify_pio; + }; + VirtIOPCIRegion regs[5]; + }; MemoryRegion modern_bar; MemoryRegion io_bar; - MemoryRegion modern_cfg; - AddressSpace modern_as; uint32_t legacy_io_bar_idx; uint32_t msix_bar_idx; uint32_t modern_io_bar_idx; diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c index 8b0d6b69cd..ce14d5ff20 100644 --- a/hw/virtio/virtio-pci.c +++ b/hw/virtio/virtio-pci.c @@ -545,6 +545,24 @@ static const MemoryRegionOps virtio_pci_config_ops =3D= { .endianness =3D DEVICE_LITTLE_ENDIAN, }; =20 +static MemoryRegion *virtio_address_space_lookup(VirtIOPCIProxy *proxy, + hwaddr *off, int len) +{ + int i; + VirtIOPCIRegion *reg; + + for (i =3D 0; i < ARRAY_SIZE(proxy->regs); ++i) { + reg =3D &proxy->regs[i]; + if (*off >=3D reg->offset && + *off + len <=3D reg->offset + reg->size) { + *off -=3D reg->offset; + return ®->mr; + } + } + + return NULL; +} + /* Below are generic functions to do memcpy from/to an address space, * without byteswaps, with input validation. * @@ -558,63 +576,72 @@ static const MemoryRegionOps virtio_pci_config_ops = =3D { * Note: host pointer must be aligned. */ static -void virtio_address_space_write(AddressSpace *as, hwaddr addr, +void virtio_address_space_write(VirtIOPCIProxy *proxy, hwaddr addr, const uint8_t *buf, int len) { - uint32_t val; + uint64_t val; + MemoryRegion *mr; =20 /* address_space_* APIs assume an aligned address. * As address is under guest control, handle illegal values. */ addr &=3D ~(len - 1); =20 + mr =3D virtio_address_space_lookup(proxy, &addr, len); + if (!mr) { + return; + } + /* Make sure caller aligned buf properly */ assert(!(((uintptr_t)buf) & (len - 1))); =20 switch (len) { case 1: val =3D pci_get_byte(buf); - address_space_stb(as, addr, val, MEMTXATTRS_UNSPECIFIED, NULL); break; case 2: - val =3D pci_get_word(buf); - address_space_stw_le(as, addr, val, MEMTXATTRS_UNSPECIFIED, NULL); + val =3D cpu_to_le16(pci_get_word(buf)); break; case 4: - val =3D pci_get_long(buf); - address_space_stl_le(as, addr, val, MEMTXATTRS_UNSPECIFIED, NULL); + val =3D cpu_to_le32(pci_get_long(buf)); break; default: /* As length is under guest control, handle illegal values. */ - break; + return; } + memory_region_dispatch_write(mr, addr, val, len, MEMTXATTRS_UNSPECIFIE= D); } =20 static void -virtio_address_space_read(AddressSpace *as, hwaddr addr, uint8_t *buf, int= len) +virtio_address_space_read(VirtIOPCIProxy *proxy, hwaddr addr, + uint8_t *buf, int len) { - uint32_t val; + uint64_t val; + MemoryRegion *mr; =20 /* address_space_* APIs assume an aligned address. * As address is under guest control, handle illegal values. */ addr &=3D ~(len - 1); =20 + mr =3D virtio_address_space_lookup(proxy, &addr, len); + if (!mr) { + return; + } + /* Make sure caller aligned buf properly */ assert(!(((uintptr_t)buf) & (len - 1))); =20 + memory_region_dispatch_read(mr, addr, &val, len, MEMTXATTRS_UNSPECIFIE= D); switch (len) { case 1: - val =3D address_space_ldub(as, addr, MEMTXATTRS_UNSPECIFIED, NULL); pci_set_byte(buf, val); break; case 2: - val =3D address_space_lduw_le(as, addr, MEMTXATTRS_UNSPECIFIED, NU= LL); - pci_set_word(buf, val); + pci_set_word(buf, le16_to_cpu(val)); break; case 4: - val =3D address_space_ldl_le(as, addr, MEMTXATTRS_UNSPECIFIED, NUL= L); - pci_set_long(buf, val); + pci_set_long(buf, le32_to_cpu(val)); break; default: /* As length is under guest control, handle illegal values. */ @@ -650,8 +677,7 @@ static void virtio_write_config(PCIDevice *pci_dev, uin= t32_t address, =20 if (len =3D=3D 1 || len =3D=3D 2 || len =3D=3D 4) { assert(len <=3D sizeof cfg->pci_cfg_data); - virtio_address_space_write(&proxy->modern_as, off, - cfg->pci_cfg_data, len); + virtio_address_space_write(proxy, off, cfg->pci_cfg_data, len); } } } @@ -675,8 +701,7 @@ static uint32_t virtio_read_config(PCIDevice *pci_dev, =20 if (len =3D=3D 1 || len =3D=3D 2 || len =3D=3D 4) { assert(len <=3D sizeof cfg->pci_cfg_data); - virtio_address_space_read(&proxy->modern_as, off, - cfg->pci_cfg_data, len); + virtio_address_space_read(proxy, off, cfg->pci_cfg_data, len); } } =20 @@ -1783,15 +1808,6 @@ static void virtio_pci_realize(PCIDevice *pci_dev, E= rror **errp) /* PCI BAR regions must be powers of 2 */ pow2ceil(proxy->notify.offset + proxy->notify.size)= ); =20 - memory_region_init_alias(&proxy->modern_cfg, - OBJECT(proxy), - "virtio-pci-cfg", - &proxy->modern_bar, - 0, - memory_region_size(&proxy->modern_bar)); - - address_space_init(&proxy->modern_as, &proxy->modern_cfg, "virtio-pci-= cfg-as"); - if (proxy->disable_legacy =3D=3D ON_OFF_AUTO_AUTO) { proxy->disable_legacy =3D pcie_port ? ON_OFF_AUTO_ON : ON_OFF_AUTO= _OFF; } @@ -1860,10 +1876,7 @@ static void virtio_pci_realize(PCIDevice *pci_dev, E= rror **errp) =20 static void virtio_pci_exit(PCIDevice *pci_dev) { - VirtIOPCIProxy *proxy =3D VIRTIO_PCI(pci_dev); - msix_uninit_exclusive_bar(pci_dev); - address_space_destroy(&proxy->modern_as); } =20 static void virtio_pci_reset(DeviceState *qdev) --=20 2.11.0