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[Qemu-devel] [PATCH] virtio-pci: use generic logic for command access
From: |
Michael S. Tsirkin |
Subject: |
[Qemu-devel] [PATCH] virtio-pci: use generic logic for command access |
Date: |
Wed, 27 Jul 2011 20:08:42 +0300 |
User-agent: |
Mutt/1.5.21 (2010-09-15) |
In practice, guests don't generate config requests
that cross a word boundary, so the logic to
detect command word access is correct because
PCI_COMMAND is 0x4. But depending on this is
tricky, further, it will break with guests
that do try to generate a misaligned access
as we pass it to devices without splitting.
Better to use the generic range_covers_byte for this.
Signed-off-by: Michael S. Tsirkin <address@hidden>
---
hw/virtio-pci.c | 18 +++++++++---------
1 files changed, 9 insertions(+), 9 deletions(-)
diff --git a/hw/virtio-pci.c b/hw/virtio-pci.c
index d685243..4f770fe 100644
--- a/hw/virtio-pci.c
+++ b/hw/virtio-pci.c
@@ -27,6 +27,7 @@
#include "kvm.h"
#include "blockdev.h"
#include "virtio-pci.h"
+#include "range.h"
/* from Linux's linux/virtio_pci.h */
@@ -516,17 +517,16 @@ static void virtio_write_config(PCIDevice *pci_dev,
uint32_t address,
{
VirtIOPCIProxy *proxy = DO_UPCAST(VirtIOPCIProxy, pci_dev, pci_dev);
- if (PCI_COMMAND == address) {
- if (!(val & PCI_COMMAND_MASTER)) {
- if (!(proxy->flags & VIRTIO_PCI_FLAG_BUS_MASTER_BUG)) {
- virtio_pci_stop_ioeventfd(proxy);
- virtio_set_status(proxy->vdev,
- proxy->vdev->status &
~VIRTIO_CONFIG_S_DRIVER_OK);
- }
- }
+ pci_default_write_config(pci_dev, address, val, len);
+
+ if (range_covers_byte(address, len, PCI_COMMAND) &&
+ !(pci_dev->config[PCI_COMMAND] & PCI_COMMAND_MASTER) &&
+ !(proxy->flags & VIRTIO_PCI_FLAG_BUS_MASTER_BUG)) {
+ virtio_pci_stop_ioeventfd(proxy);
+ virtio_set_status(proxy->vdev,
+ proxy->vdev->status & ~VIRTIO_CONFIG_S_DRIVER_OK);
}
- pci_default_write_config(pci_dev, address, val, len);
msix_write_config(pci_dev, address, val, len);
}
--
1.7.5.53.gc233e
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