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Re: [Qemu-devel] [PATCH v7 04/13] vfio: Add save and load functions for
From: |
Dr. David Alan Gilbert |
Subject: |
Re: [Qemu-devel] [PATCH v7 04/13] vfio: Add save and load functions for VFIO PCI devices |
Date: |
Thu, 11 Jul 2019 13:07:13 +0100 |
User-agent: |
Mutt/1.12.0 (2019-05-25) |
* Kirti Wankhede (address@hidden) 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 <address@hidden>
> Reviewed-by: Neo Jia <address@hidden>
> ---
> 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.
> + 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.
Also, are the other flags in COMMAND safe at this point - e.g. what
about interrupts and stuff?
> + 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 / address@hidden / Manchester, UK
- [Qemu-devel] [PATCH v7 01/13] vfio: KABI for migration interface, (continued)
- [Qemu-devel] [PATCH v7 01/13] vfio: KABI for migration interface, Kirti Wankhede, 2019/07/09
- [Qemu-devel] [PATCH v7 02/13] vfio: Add function to unmap VFIO region, Kirti Wankhede, 2019/07/09
- [Qemu-devel] [PATCH v7 03/13] vfio: Add vfio_get_object callback to VFIODeviceOps, Kirti Wankhede, 2019/07/09
- [Qemu-devel] [PATCH v7 04/13] vfio: Add save and load functions for VFIO PCI devices, Kirti Wankhede, 2019/07/09
- [Qemu-devel] [PATCH v7 05/13] vfio: Add migration region initialization and finalize function, Kirti Wankhede, 2019/07/09
- [Qemu-devel] [PATCH v7 06/13] vfio: Add VM state change handler to know state of VM, Kirti Wankhede, 2019/07/09