Commit e638073c authored by Bandan Das's avatar Bandan Das Committed by Alex Williamson
Browse files

vfio: Do not reattempt a failed rom read 



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: default avatarBandan Das <bsd@redhat.com>
Signed-off-by: default avatarAlex Williamson <alex.williamson@redhat.com>
parent d20b43df

hw/misc/vfio.c

+6 −0
Original line number Diff line number Diff line
@@ -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,