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[Qemu-devel] [PULL 23/26] virtio-pci: Replace modern_as with direct acce
From: |
Michael S. Tsirkin |
Subject: |
[Qemu-devel] [PULL 23/26] virtio-pci: Replace modern_as with direct access to modern_bar |
Date: |
Sun, 15 Oct 2017 06:24:00 +0300 |
From: Alexey Kardashevskiy <address@hidden>
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 <address@hidden>
Reviewed-by: Michael S. Tsirkin <address@hidden>
Signed-off-by: Michael S. Tsirkin <address@hidden>
---
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 69f5959..12d3a90 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 6c60aa0..e92837c 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -491,6 +491,24 @@ static const MemoryRegionOps virtio_pci_config_ops = {
.endianness = DEVICE_LITTLE_ENDIAN,
};
+static MemoryRegion *virtio_address_space_lookup(VirtIOPCIProxy *proxy,
+ hwaddr *off, int len)
+{
+ int i;
+ VirtIOPCIRegion *reg;
+
+ for (i = 0; i < ARRAY_SIZE(proxy->regs); ++i) {
+ reg = &proxy->regs[i];
+ if (*off >= reg->offset &&
+ *off + len <= reg->offset + reg->size) {
+ *off -= reg->offset;
+ return ®->mr;
+ }
+ }
+
+ return NULL;
+}
+
/* Below are generic functions to do memcpy from/to an address space,
* without byteswaps, with input validation.
*
@@ -504,63 +522,72 @@ static const MemoryRegionOps virtio_pci_config_ops = {
* 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;
/* address_space_* APIs assume an aligned address.
* As address is under guest control, handle illegal values.
*/
addr &= ~(len - 1);
+ mr = virtio_address_space_lookup(proxy, &addr, len);
+ if (!mr) {
+ return;
+ }
+
/* Make sure caller aligned buf properly */
assert(!(((uintptr_t)buf) & (len - 1)));
switch (len) {
case 1:
val = pci_get_byte(buf);
- address_space_stb(as, addr, val, MEMTXATTRS_UNSPECIFIED, NULL);
break;
case 2:
- val = pci_get_word(buf);
- address_space_stw_le(as, addr, val, MEMTXATTRS_UNSPECIFIED, NULL);
+ val = cpu_to_le16(pci_get_word(buf));
break;
case 4:
- val = pci_get_long(buf);
- address_space_stl_le(as, addr, val, MEMTXATTRS_UNSPECIFIED, NULL);
+ val = 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_UNSPECIFIED);
}
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;
/* address_space_* APIs assume an aligned address.
* As address is under guest control, handle illegal values.
*/
addr &= ~(len - 1);
+ mr = virtio_address_space_lookup(proxy, &addr, len);
+ if (!mr) {
+ return;
+ }
+
/* Make sure caller aligned buf properly */
assert(!(((uintptr_t)buf) & (len - 1)));
+ memory_region_dispatch_read(mr, addr, &val, len, MEMTXATTRS_UNSPECIFIED);
switch (len) {
case 1:
- val = address_space_ldub(as, addr, MEMTXATTRS_UNSPECIFIED, NULL);
pci_set_byte(buf, val);
break;
case 2:
- val = address_space_lduw_le(as, addr, MEMTXATTRS_UNSPECIFIED, NULL);
- pci_set_word(buf, val);
+ pci_set_word(buf, le16_to_cpu(val));
break;
case 4:
- val = address_space_ldl_le(as, addr, MEMTXATTRS_UNSPECIFIED, NULL);
- pci_set_long(buf, val);
+ pci_set_long(buf, le32_to_cpu(val));
break;
default:
/* As length is under guest control, handle illegal values. */
@@ -596,8 +623,7 @@ static void virtio_write_config(PCIDevice *pci_dev,
uint32_t address,
if (len == 1 || len == 2 || len == 4) {
assert(len <= 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);
}
}
}
@@ -621,8 +647,7 @@ static uint32_t virtio_read_config(PCIDevice *pci_dev,
if (len == 1 || len == 2 || len == 4) {
assert(len <= 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);
}
}
@@ -1729,15 +1754,6 @@ static void virtio_pci_realize(PCIDevice *pci_dev, Error
**errp)
/* PCI BAR regions must be powers of 2 */
pow2ceil(proxy->notify.offset + proxy->notify.size));
- 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 == ON_OFF_AUTO_AUTO) {
proxy->disable_legacy = pcie_port ? ON_OFF_AUTO_ON : ON_OFF_AUTO_OFF;
}
@@ -1806,10 +1822,7 @@ static void virtio_pci_realize(PCIDevice *pci_dev, Error
**errp)
static void virtio_pci_exit(PCIDevice *pci_dev)
{
- VirtIOPCIProxy *proxy = VIRTIO_PCI(pci_dev);
-
msix_uninit_exclusive_bar(pci_dev);
- address_space_destroy(&proxy->modern_as);
}
static void virtio_pci_reset(DeviceState *qdev)
--
MST
- [Qemu-devel] [PULL 13/26] virtio/pci/migration: Convert to VMState, (continued)
- [Qemu-devel] [PULL 13/26] virtio/pci/migration: Convert to VMState, Michael S. Tsirkin, 2017/10/14
- [Qemu-devel] [PULL 14/26] PCI: PCIe access should always be little endian, Michael S. Tsirkin, 2017/10/14
- [Qemu-devel] [PULL 15/26] pci: conventional-pci-device and pci-express-device interfaces, Michael S. Tsirkin, 2017/10/14
- [Qemu-devel] [PULL 16/26] pci: Add interface names to hybrid PCI devices, Michael S. Tsirkin, 2017/10/14
- [Qemu-devel] [PULL 17/26] pci: Add INTERFACE_PCIE_DEVICE to all PCIe devices, Michael S. Tsirkin, 2017/10/14
- [Qemu-devel] [PULL 19/26] xen/pt: Mark TYPE_XEN_PT_DEVICE as hybrid, Michael S. Tsirkin, 2017/10/14
- [Qemu-devel] [PULL 20/26] pci: Validate interfaces on base_class_init, Michael S. Tsirkin, 2017/10/14
- [Qemu-devel] [PULL 21/26] hw/gen_pcie_root_port: make IO RO 0 on IO disabled, Michael S. Tsirkin, 2017/10/14
- [Qemu-devel] [PULL 22/26] virtio: fix descriptor counting in virtqueue_pop, Michael S. Tsirkin, 2017/10/14
- [Qemu-devel] [PULL 24/26] isapc: Remove unnecessary migration compatibility code, Michael S. Tsirkin, 2017/10/14
- [Qemu-devel] [PULL 23/26] virtio-pci: Replace modern_as with direct access to modern_bar,
Michael S. Tsirkin <=
- [Qemu-devel] [PULL 25/26] pc: remove useless hot_add_cpu initialisation, Michael S. Tsirkin, 2017/10/14
- [Qemu-devel] [PULL 26/26] tests/pxe: Test more NICs when running in SPEED=slow mode, Michael S. Tsirkin, 2017/10/14
- [Qemu-devel] [PULL 18/26] pci: Add INTERFACE_CONVENTIONAL_PCI_DEVICE to Conventional PCI devices, Michael S. Tsirkin, 2017/10/14
- Re: [Qemu-devel] [PULL 00/26] pc, pci, virtio: fixes, features, Peter Maydell, 2017/10/16