From ba6090ff8ae01b41288be87ed9f6bed3d8cf5961 Mon Sep 17 00:00:00 2001
From: Matthew Rosato <mjrosato@linux.ibm.com>
Date: Mon, 6 Jun 2022 16:33:23 -0400
Subject: [PATCH] vfio-pci/zdev: different maxstbl for interpreted devices
When doing load/store interpretation, the maximum store block length is
determined by the underlying firmware, not the host kernel API. Reflect
that in the associated Query PCI Function Group clp capability and let
userspace decide which is appropriate to present to the guest.
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Link: https://lore.kernel.org/r/20220606203325.110625-20-mjrosato@linux.ibm.com
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
---
drivers/vfio/pci/vfio_pci_zdev.c | 6 ++++--
include/uapi/linux/vfio_zdev.h | 4 ++++
2 files changed, 8 insertions(+), 2 deletions(-)
diff --git a/drivers/vfio/pci/vfio_pci_zdev.c b/drivers/vfio/pci/vfio_pci_zdev.c
index 4f28cdd7ecd1c..e163aa9f61444 100644
--- a/drivers/vfio/pci/vfio_pci_zdev.c
+++ b/drivers/vfio/pci/vfio_pci_zdev.c
@@ -45,14 +45,16 @@ static int zpci_group_cap(struct zpci_dev *zdev, struct vfio_info_cap *caps)
{
struct vfio_device_info_cap_zpci_group cap = {
.header.id = VFIO_DEVICE_INFO_CAP_ZPCI_GROUP,
- .header.version = 1,
+ .header.version = 2,
.dasm = zdev->dma_mask,
.msi_addr = zdev->msi_addr,
.flags = VFIO_DEVICE_INFO_ZPCI_FLAG_REFRESH,
.mui = zdev->fmb_update,
.noi = zdev->max_msi,
.maxstbl = ZPCI_MAX_WRITE_SIZE,
- .version = zdev->version
+ .version = zdev->version,
+ .reserved = 0,
+ .imaxstbl = zdev->maxstbl
};
return vfio_info_add_capability(caps, &cap.header, sizeof(cap));
diff --git a/include/uapi/linux/vfio_zdev.h b/include/uapi/linux/vfio_zdev.h
index 78c022af3d29a..77f2aff1f27e9 100644
--- a/include/uapi/linux/vfio_zdev.h
+++ b/include/uapi/linux/vfio_zdev.h
@@ -50,6 +50,10 @@ struct vfio_device_info_cap_zpci_group {
__u16 noi; /* Maximum number of MSIs */
__u16 maxstbl; /* Maximum Store Block Length */
__u8 version; /* Supported PCI Version */
+ /* End of version 1 */
+ __u8 reserved;
+ __u16 imaxstbl; /* Maximum Interpreted Store Block Length */
+ /* End of version 2 */
};
/**
--
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