RE: [PATCH v1] vfio/common: Separate vfio-pci ranges

[Duan, Zhenzhong]

>-----Original Message-----
>From: qemu-devel-bounces+zhenzhong.duan=intel.com@nongnu.org <qemu-
>devel-bounces+zhenzhong.duan=intel.com@nongnu.org> On Behalf Of Joao
>Martins
>Sent: Friday, September 8, 2023 5:30 PM
>Subject: [PATCH v1] vfio/common: Separate vfio-pci ranges
>
>QEMU computes the DMA logging ranges for two predefined ranges: 32-bit
>and 64-bit. In the OVMF case, when the dynamic MMIO window is enabled,
>QEMU includes in the 64-bit range the RAM regions at the lower part
>and vfio-pci device RAM regions which are at the top of the address
>space. This range contains a large gap and the size can be bigger than
>the dirty tracking HW limits of some devices (MLX5 has a 2^42 limit).
>
>To avoid such large ranges, introduce a new PCI range covering the
>vfio-pci device RAM regions, this only if the addresses are above 4GB
>to avoid breaking potential SeaBIOS guests.
>
>Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
>[ clg: - wrote commit log
>       - fixed overlapping 32-bit and PCI ranges when using SeaBIOS ]
>Signed-off-by: Cédric Le Goater <clg@redhat.com>
>---
>v2:
>* s/minpci/minpci64/
>* s/maxpci/maxpci64/
>* Expand comment to cover the pci-hole64 and why we don't do special
>  handling of pci-hole32.
>---
> hw/vfio/common.c     | 71 +++++++++++++++++++++++++++++++++++++-------
> hw/vfio/trace-events |  2 +-
> 2 files changed, 61 insertions(+), 12 deletions(-)
>
>diff --git a/hw/vfio/common.c b/hw/vfio/common.c
>index 237101d03844..134649226d43 100644
>--- a/hw/vfio/common.c
>+++ b/hw/vfio/common.c
>@@ -27,6 +27,7 @@
>
> #include "hw/vfio/vfio-common.h"
> #include "hw/vfio/vfio.h"
>+#include "hw/vfio/pci.h"
> #include "exec/address-spaces.h"
> #include "exec/memory.h"
> #include "exec/ram_addr.h"
>@@ -1400,6 +1401,8 @@ typedef struct VFIODirtyRanges {
>     hwaddr max32;
>     hwaddr min64;
>     hwaddr max64;
>+    hwaddr minpci64;
>+    hwaddr maxpci64;
> } VFIODirtyRanges;
>
> typedef struct VFIODirtyRangesListener {
>@@ -1408,6 +1411,31 @@ typedef struct VFIODirtyRangesListener {
>     MemoryListener listener;
> } VFIODirtyRangesListener;
>
>+static bool vfio_section_is_vfio_pci(MemoryRegionSection *section,
>+                                     VFIOContainer *container)
>+{
>+    VFIOPCIDevice *pcidev;
>+    VFIODevice *vbasedev;
>+    VFIOGroup *group;
>+    Object *owner;
>+
>+    owner = memory_region_owner(section->mr);
>+
>+    QLIST_FOREACH(group, &container->group_list, container_next) {
>+        QLIST_FOREACH(vbasedev, &group->device_list, next) {
>+            if (vbasedev->type != VFIO_DEVICE_TYPE_PCI) {
>+                continue;
>+            }
>+            pcidev = container_of(vbasedev, VFIOPCIDevice, vbasedev);
>+            if (OBJECT(pcidev) == owner) {
>+                return true;
>+            }
>+        }
>+    }
>+
>+    return false;
>+}

What about simplify it with memory_region_is_ram_device()?
This way vdpa device could also be included.

Thanks
Zhenzhong