Sorry for delay to respond.
On 7/11/2019 5:37 PM, Dr. David Alan Gilbert wrote:
> * Kirti Wankhede (kwankh...@nvidia.com) wrote:
>> These functions save and restore PCI device specific data - config
>> space of PCI device.
>> Tested save and restore with MSI and MSIX type.
>>
>> Signed-off-by: Kirti Wankhede <kwankh...@nvidia.com>
>> Reviewed-by: Neo Jia <c...@nvidia.com>
>> ---
>> hw/vfio/pci.c | 114
>> ++++++++++++++++++++++++++++++++++++++++++
>> include/hw/vfio/vfio-common.h | 2 +
>> 2 files changed, 116 insertions(+)
>>
>> diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
>> index de0d286fc9dd..5fe4f8076cac 100644
>> --- a/hw/vfio/pci.c
>> +++ b/hw/vfio/pci.c
>> @@ -2395,11 +2395,125 @@ static Object *vfio_pci_get_object(VFIODevice
>> *vbasedev)
>> return OBJECT(vdev);
>> }
>>
>> +static void vfio_pci_save_config(VFIODevice *vbasedev, QEMUFile *f)
>> +{
>> + VFIOPCIDevice *vdev = container_of(vbasedev, VFIOPCIDevice, vbasedev);
>> + PCIDevice *pdev = &vdev->pdev;
>> + uint16_t pci_cmd;
>> + int i;
>> +
>> + for (i = 0; i < PCI_ROM_SLOT; i++) {
>> + uint32_t bar;
>> +
>> + bar = pci_default_read_config(pdev, PCI_BASE_ADDRESS_0 + i * 4, 4);
>> + qemu_put_be32(f, bar);
>> + }
>> +
>> + qemu_put_be32(f, vdev->interrupt);
>> + if (vdev->interrupt == VFIO_INT_MSI) {
>> + uint32_t msi_flags, msi_addr_lo, msi_addr_hi = 0, msi_data;
>> + bool msi_64bit;
>> +
>> + msi_flags = pci_default_read_config(pdev, pdev->msi_cap +
>> PCI_MSI_FLAGS,
>> + 2);
>> + msi_64bit = (msi_flags & PCI_MSI_FLAGS_64BIT);
>> +
>> + msi_addr_lo = pci_default_read_config(pdev,
>> + pdev->msi_cap +
>> PCI_MSI_ADDRESS_LO, 4);
>> + qemu_put_be32(f, msi_addr_lo);
>> +
>> + if (msi_64bit) {
>> + msi_addr_hi = pci_default_read_config(pdev,
>> + pdev->msi_cap +
>> PCI_MSI_ADDRESS_HI,
>> + 4);
>> + }
>> + qemu_put_be32(f, msi_addr_hi);
>> +
>> + msi_data = pci_default_read_config(pdev,
>> + pdev->msi_cap + (msi_64bit ? PCI_MSI_DATA_64 :
>> PCI_MSI_DATA_32),
>> + 2);
>> + qemu_put_be32(f, msi_data);
>> + } else if (vdev->interrupt == VFIO_INT_MSIX) {
>> + uint16_t offset;
>> +
>> + /* save enable bit and maskall bit */
>> + offset = pci_default_read_config(pdev,
>> + pdev->msix_cap + PCI_MSIX_FLAGS + 1,
>> 2);
>> + qemu_put_be16(f, offset);
>> + msix_save(pdev, f);
>> + }
>> + pci_cmd = pci_default_read_config(pdev, PCI_COMMAND, 2);
>> + qemu_put_be16(f, pci_cmd);
>> +}
>> +
>> +static void vfio_pci_load_config(VFIODevice *vbasedev, QEMUFile *f)
>> +{
>> + VFIOPCIDevice *vdev = container_of(vbasedev, VFIOPCIDevice, vbasedev);
>> + PCIDevice *pdev = &vdev->pdev;
>> + uint32_t interrupt_type;
>> + uint32_t msi_flags, msi_addr_lo, msi_addr_hi = 0, msi_data;
>> + uint16_t pci_cmd;
>> + bool msi_64bit;
>> + int i;
>> +
>> + /* retore pci bar configuration */
>> + pci_cmd = pci_default_read_config(pdev, PCI_COMMAND, 2);
>> + vfio_pci_write_config(pdev, PCI_COMMAND,
>> + pci_cmd & (!(PCI_COMMAND_IO | PCI_COMMAND_MEMORY)),
>> 2);
>> + for (i = 0; i < PCI_ROM_SLOT; i++) {
>> + uint32_t bar = qemu_get_be32(f);
>> +
>> + vfio_pci_write_config(pdev, PCI_BASE_ADDRESS_0 + i * 4, bar, 4);
>> + }
>
> Is it possible to validate the bar's at all? We just had a bug on a
> virtual device where one version was asking for a larger bar than the
> other; our validation caught this in some cases so we could tell that
> the guest had a BAR that was aligned at the wrong alignment.
>
"Validate the bars" does that means validate size of bars?
>> + vfio_pci_write_config(pdev, PCI_COMMAND,
>> + pci_cmd | PCI_COMMAND_IO | PCI_COMMAND_MEMORY, 2);
>
> Can you explain what this is for? You write the command register at the
> end of the function with the original value; there's no guarantee that
> the device is using IO for example, so ORing it seems odd.
>
IO space and memory space accesses are disabled before writing BAR
addresses, only those are enabled here.
> Also, are the other flags in COMMAND safe at this point - e.g. what
> about interrupts and stuff?
>
COMMAND registers is saved from stop-and-copy phase, interrupt should be
disabled, then restoring here when vCPU are not yet running.
>> + interrupt_type = qemu_get_be32(f);
>> +
>> + if (interrupt_type == VFIO_INT_MSI) {
>> + /* restore msi configuration */
>> + msi_flags = pci_default_read_config(pdev,
>> + pdev->msi_cap + PCI_MSI_FLAGS,
>> 2);
>> + msi_64bit = (msi_flags & PCI_MSI_FLAGS_64BIT);
>> +
>> + vfio_pci_write_config(pdev, pdev->msi_cap + PCI_MSI_FLAGS,
>> + msi_flags & (!PCI_MSI_FLAGS_ENABLE), 2);
>> +
>> + msi_addr_lo = qemu_get_be32(f);
>> + vfio_pci_write_config(pdev, pdev->msi_cap + PCI_MSI_ADDRESS_LO,
>> + msi_addr_lo, 4);
>> +
>> + msi_addr_hi = qemu_get_be32(f);
>> + if (msi_64bit) {
>> + vfio_pci_write_config(pdev, pdev->msi_cap + PCI_MSI_ADDRESS_HI,
>> + msi_addr_hi, 4);
>> + }
>> + msi_data = qemu_get_be32(f);
>> + vfio_pci_write_config(pdev,
>> + pdev->msi_cap + (msi_64bit ? PCI_MSI_DATA_64 :
>> PCI_MSI_DATA_32),
>> + msi_data, 2);
>> +
>> + vfio_pci_write_config(pdev, pdev->msi_cap + PCI_MSI_FLAGS,
>> + msi_flags | PCI_MSI_FLAGS_ENABLE, 2);
>> + } else if (interrupt_type == VFIO_INT_MSIX) {
>> + uint16_t offset = qemu_get_be16(f);
>> +
>> + /* load enable bit and maskall bit */
>> + vfio_pci_write_config(pdev, pdev->msix_cap + PCI_MSIX_FLAGS + 1,
>> + offset, 2);
>> + msix_load(pdev, f);
>> + }
>> + pci_cmd = qemu_get_be16(f);
>> + vfio_pci_write_config(pdev, PCI_COMMAND, pci_cmd, 2);
>> +}
>> +
>> static VFIODeviceOps vfio_pci_ops = {
>> .vfio_compute_needs_reset = vfio_pci_compute_needs_reset,
>> .vfio_hot_reset_multi = vfio_pci_hot_reset_multi,
>> .vfio_eoi = vfio_intx_eoi,
>> .vfio_get_object = vfio_pci_get_object,
>> + .vfio_save_config = vfio_pci_save_config,
>> + .vfio_load_config = vfio_pci_load_config,
>> };
>>
>> int vfio_populate_vga(VFIOPCIDevice *vdev, Error **errp)
>> diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
>> index 771b6d59a3db..ee72bd984a36 100644
>> --- a/include/hw/vfio/vfio-common.h
>> +++ b/include/hw/vfio/vfio-common.h
>> @@ -120,6 +120,8 @@ struct VFIODeviceOps {
>> int (*vfio_hot_reset_multi)(VFIODevice *vdev);
>> void (*vfio_eoi)(VFIODevice *vdev);
>> Object *(*vfio_get_object)(VFIODevice *vdev);
>> + void (*vfio_save_config)(VFIODevice *vdev, QEMUFile *f);
>> + void (*vfio_load_config)(VFIODevice *vdev, QEMUFile *f);
>> };
>>
>> typedef struct VFIOGroup {
>> --
>> 2.7.0
>>
> --
> Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
>
