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[Qemu-devel] [PULL 3/7] vfio: Do not reattempt a failed rom read
From: |
Alex Williamson |
Subject: |
[Qemu-devel] [PULL 3/7] vfio: Do not reattempt a failed rom read |
Date: |
Fri, 17 Jan 2014 12:25:26 -0700 |
User-agent: |
StGit/0.17-dirty |
From: Bandan Das <address@hidden>
During lazy rom loading, if rom read fails, and the
guest attempts a read again, vfio will again attempt it.
Add a boolean to prevent this. There could be a case where
a failed rom read might succeed the next time because of
a device reset or such, but it's best to exclude unpredictable
behavior
Signed-off-by: Bandan Das <address@hidden>
Signed-off-by: Alex Williamson <address@hidden>
---
hw/misc/vfio.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/hw/misc/vfio.c b/hw/misc/vfio.c
index ef615fc..30b1a78 100644
--- a/hw/misc/vfio.c
+++ b/hw/misc/vfio.c
@@ -191,6 +191,7 @@ typedef struct VFIODevice {
bool has_flr;
bool has_pm_reset;
bool needs_reset;
+ bool rom_read_failed;
} VFIODevice;
typedef struct VFIOGroup {
@@ -1125,6 +1126,7 @@ static void vfio_pci_load_rom(VFIODevice *vdev)
vdev->rom_offset = reg_info.offset;
if (!vdev->rom_size) {
+ vdev->rom_read_failed = true;
error_report("vfio-pci: Cannot read device rom at "
"%04x:%02x:%02x.%x\n",
vdev->host.domain, vdev->host.bus, vdev->host.slot,
@@ -1163,6 +1165,9 @@ static uint64_t vfio_rom_read(void *opaque, hwaddr addr,
unsigned size)
/* Load the ROM lazily when the guest tries to read it */
if (unlikely(!vdev->rom)) {
vfio_pci_load_rom(vdev);
+ if (unlikely(!vdev->rom && !vdev->rom_read_failed)) {
+ vfio_pci_load_rom(vdev);
+ }
}
memcpy(&val, vdev->rom + addr,
@@ -1230,6 +1235,7 @@ static void vfio_pci_size_rom(VFIODevice *vdev)
PCI_BASE_ADDRESS_SPACE_MEMORY, &vdev->pdev.rom);
vdev->pdev.has_rom = true;
+ vdev->rom_read_failed = false;
}
static void vfio_vga_write(void *opaque, hwaddr addr,
- [Qemu-devel] [PULL 0/7] vfio pull request, Alex Williamson, 2014/01/17
- [Qemu-devel] [PULL 1/7] vfio: Destroy memory regions, Alex Williamson, 2014/01/17
- [Qemu-devel] [PULL 2/7] vfio: warn if host device rom can't be read, Alex Williamson, 2014/01/17
- [Qemu-devel] [PULL 3/7] vfio: Do not reattempt a failed rom read,
Alex Williamson <=
- [Qemu-devel] [PULL 4/7] vfio: Filter out bogus mappings, Alex Williamson, 2014/01/17
- [Qemu-devel] [PULL 5/7] vfio-pci: Fail initfn on DMA mapping errors, Alex Williamson, 2014/01/17
- [Qemu-devel] [PULL 6/7] kvm: initialize qemu_host_page_size, Alex Williamson, 2014/01/17
- [Qemu-devel] [PULL 7/7] vfio: fix mapping of MSIX bar, Alex Williamson, 2014/01/17