>-----Original Message-----
>From: Joao Martins <joao.m.mart...@oracle.com>
>Sent: Friday, July 19, 2024 8:05 PM
>To: qemu-devel@nongnu.org
>Cc: Liu, Yi L <yi.l....@intel.com>; Eric Auger <eric.au...@redhat.com>; Duan,
>Zhenzhong <zhenzhong.d...@intel.com>; Alex Williamson
><alex.william...@redhat.com>; Cedric Le Goater <c...@redhat.com>; Jason
>Gunthorpe <j...@nvidia.com>; Avihai Horon <avih...@nvidia.com>; Joao
>Martins <joao.m.mart...@oracle.com>
>Subject: [PATCH v5 01/13] vfio/pci: Extract mdev check into an helper
>
>In preparation to skip initialization of the HostIOMMUDevice for mdev,
>extract the checks that validate if a device is an mdev into helpers.
>
>A vfio_device_is_mdev() is created, and subsystems consult
>VFIODevice::mdev
>to check if it's mdev or not.
>
>Signed-off-by: Joao Martins <joao.m.mart...@oracle.com>
Reviewed-by: Zhenzhong Duan <zhenzhong.d...@intel.com>
Thanks
Zhenzhong
>---
> include/hw/vfio/vfio-common.h | 2 ++
> hw/vfio/helpers.c | 14 ++++++++++++++
> hw/vfio/pci.c | 12 +++---------
> 3 files changed, 19 insertions(+), 9 deletions(-)
>
>diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-
>common.h
>index e8ddf92bb185..98acae8c1c97 100644
>--- a/include/hw/vfio/vfio-common.h
>+++ b/include/hw/vfio/vfio-common.h
>@@ -116,6 +116,7 @@ typedef struct VFIODevice {
> DeviceState *dev;
> int fd;
> int type;
>+ bool mdev;
> bool reset_works;
> bool needs_reset;
> bool no_mmap;
>@@ -231,6 +232,7 @@ void vfio_region_exit(VFIORegion *region);
> void vfio_region_finalize(VFIORegion *region);
> void vfio_reset_handler(void *opaque);
> struct vfio_device_info *vfio_get_device_info(int fd);
>+bool vfio_device_is_mdev(VFIODevice *vbasedev);
> bool vfio_attach_device(char *name, VFIODevice *vbasedev,
> AddressSpace *as, Error **errp);
> void vfio_detach_device(VFIODevice *vbasedev);
>diff --git a/hw/vfio/helpers.c b/hw/vfio/helpers.c
>index b14edd46edc9..7e23e9080c9d 100644
>--- a/hw/vfio/helpers.c
>+++ b/hw/vfio/helpers.c
>@@ -675,3 +675,17 @@ int vfio_device_get_aw_bits(VFIODevice *vdev)
>
> return HOST_IOMMU_DEVICE_CAP_AW_BITS_MAX;
> }
>+
>+bool vfio_device_is_mdev(VFIODevice *vbasedev)
>+{
>+ g_autofree char *subsys = NULL;
>+ g_autofree char *tmp = NULL;
>+
>+ if (!vbasedev->sysfsdev) {
>+ return false;
>+ }
>+
>+ tmp = g_strdup_printf("%s/subsystem", vbasedev->sysfsdev);
>+ subsys = realpath(tmp, NULL);
>+ return subsys && (strcmp(subsys, "/sys/bus/mdev") == 0);
>+}
>diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
>index e03d9f3ba546..b34e91468a53 100644
>--- a/hw/vfio/pci.c
>+++ b/hw/vfio/pci.c
>@@ -2963,12 +2963,9 @@ static void vfio_realize(PCIDevice *pdev, Error
>**errp)
> ERRP_GUARD();
> VFIOPCIDevice *vdev = VFIO_PCI(pdev);
> VFIODevice *vbasedev = &vdev->vbasedev;
>- char *subsys;
> int i, ret;
>- bool is_mdev;
> char uuid[UUID_STR_LEN];
> g_autofree char *name = NULL;
>- g_autofree char *tmp = NULL;
>
> if (vbasedev->fd < 0 && !vbasedev->sysfsdev) {
> if (!(~vdev->host.domain || ~vdev->host.bus ||
>@@ -2997,14 +2994,11 @@ static void vfio_realize(PCIDevice *pdev, Error
>**errp)
> * stays in sync with the active working set of the guest driver. Prevent
> * the x-balloon-allowed option unless this is minimally an mdev device.
> */
>- tmp = g_strdup_printf("%s/subsystem", vbasedev->sysfsdev);
>- subsys = realpath(tmp, NULL);
>- is_mdev = subsys && (strcmp(subsys, "/sys/bus/mdev") == 0);
>- free(subsys);
>+ vbasedev->mdev = vfio_device_is_mdev(vbasedev);
>
>- trace_vfio_mdev(vbasedev->name, is_mdev);
>+ trace_vfio_mdev(vbasedev->name, vbasedev->mdev);
>
>- if (vbasedev->ram_block_discard_allowed && !is_mdev) {
>+ if (vbasedev->ram_block_discard_allowed && !vbasedev->mdev) {
> error_setg(errp, "x-balloon-allowed only potentially compatible "
> "with mdev devices");
> goto error;
>--
>2.17.2
