qemu-kvm/kvm-vfio-common-remove-spurious-tpm-crb-cmd-misalignment.patch

From b90a5878355bd549200ed1eff52ea084325bfc8a Mon Sep 17 00:00:00 2001
From: Eric Auger <eric.auger@redhat.com>
Date: Fri, 6 May 2022 15:25:10 +0200
Subject: [PATCH 5/5] vfio/common: remove spurious tpm-crb-cmd misalignment
 warning
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RH-Author: Eric Auger <eric.auger@redhat.com>
RH-MergeRequest: 84: vfio/common: Remove spurious tpm-crb-cmd misalignment warning
RH-Commit: [2/2] 9b73a9aec59cb50d5e3468cc553464bf4a73d0a1 (eauger1/centos-qemu-kvm)
RH-Bugzilla: 2037612
RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>
RH-Acked-by: Cornelia Huck <cohuck@redhat.com>
RH-Acked-by: Andrew Jones <drjones@redhat.com>

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2037612
Brew: https://brewweb.engineering.redhat.com/brew/taskinfo?taskID=45166961
Upstream Status: YES
Tested: With TPM-CRB and VFIO

The CRB command buffer currently is a RAM MemoryRegion and given
its base address alignment, it causes an error report on
vfio_listener_region_add(). This region could have been a RAM device
region, easing the detection of such safe situation but this option
was not well received. So let's add a helper function that uses the
memory region owner type to detect the situation is safe wrt
the assignment. Other device types can be checked here if such kind
of problem occurs again.

Conflicts in hw/vfio/common.c
We don't have 8e3b0cbb721 ("Replace qemu_real_host_page variables with inlined functions")

Signed-off-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Acked-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Link: https://lore.kernel.org/r/20220506132510.1847942-3-eric.auger@redhat.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
(cherry picked from commit 851d6d1a0ff29a87ec588205842edf6b86d99b5c)
Signed-off-by: Eric Auger <eric.auger@redhat.com>
---
 hw/vfio/common.c     | 27 ++++++++++++++++++++++++++-
 hw/vfio/trace-events |  1 +
 2 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index 080046e3f5..0fbe0d47af 100644
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -40,6 +40,7 @@
 #include "trace.h"
 #include "qapi/error.h"
 #include "migration/migration.h"
+#include "sysemu/tpm.h"
 
 VFIOGroupList vfio_group_list =
     QLIST_HEAD_INITIALIZER(vfio_group_list);
@@ -861,6 +862,22 @@ static void vfio_unregister_ram_discard_listener(VFIOContainer *container,
     g_free(vrdl);
 }
 
+static bool vfio_known_safe_misalignment(MemoryRegionSection *section)
+{
+    MemoryRegion *mr = section->mr;
+
+    if (!TPM_IS_CRB(mr->owner)) {
+        return false;
+    }
+
+    /* this is a known safe misaligned region, just trace for debug purpose */
+    trace_vfio_known_safe_misalignment(memory_region_name(mr),
+                                       section->offset_within_address_space,
+                                       section->offset_within_region,
+                                       qemu_real_host_page_size);
+    return true;
+}
+
 static void vfio_listener_region_add(MemoryListener *listener,
                                      MemoryRegionSection *section)
 {
@@ -884,7 +901,15 @@ static void vfio_listener_region_add(MemoryListener *listener,
     if (unlikely((section->offset_within_address_space &
                   ~qemu_real_host_page_mask) !=
                  (section->offset_within_region & ~qemu_real_host_page_mask))) {
-        error_report("%s received unaligned region", __func__);
+        if (!vfio_known_safe_misalignment(section)) {
+            error_report("%s received unaligned region %s iova=0x%"PRIx64
+                         " offset_within_region=0x%"PRIx64
+                         " qemu_real_host_page_size=0x%"PRIxPTR,
+                         __func__, memory_region_name(section->mr),
+                         section->offset_within_address_space,
+                         section->offset_within_region,
+                         qemu_real_host_page_size);
+        }
         return;
     }
 
diff --git a/hw/vfio/trace-events b/hw/vfio/trace-events
index 0ef1b5f4a6..582882db91 100644
--- a/hw/vfio/trace-events
+++ b/hw/vfio/trace-events
@@ -100,6 +100,7 @@ vfio_listener_region_add_skip(uint64_t start, uint64_t end) "SKIPPING region_add
 vfio_spapr_group_attach(int groupfd, int tablefd) "Attached groupfd %d to liobn fd %d"
 vfio_listener_region_add_iommu(uint64_t start, uint64_t end) "region_add [iommu] 0x%"PRIx64" - 0x%"PRIx64
 vfio_listener_region_add_ram(uint64_t iova_start, uint64_t iova_end, void *vaddr) "region_add [ram] 0x%"PRIx64" - 0x%"PRIx64" [%p]"
+vfio_known_safe_misalignment(const char *name, uint64_t iova, uint64_t offset_within_region, uintptr_t page_size) "Region \"%s\" iova=0x%"PRIx64" offset_within_region=0x%"PRIx64" qemu_real_host_page_size=0x%"PRIxPTR ": cannot be mapped for DMA"
 vfio_listener_region_add_no_dma_map(const char *name, uint64_t iova, uint64_t size, uint64_t page_size) "Region \"%s\" 0x%"PRIx64" size=0x%"PRIx64" is not aligned to 0x%"PRIx64" and cannot be mapped for DMA"
 vfio_listener_region_del_skip(uint64_t start, uint64_t end) "SKIPPING region_del 0x%"PRIx64" - 0x%"PRIx64
 vfio_listener_region_del(uint64_t start, uint64_t end) "region_del 0x%"PRIx64" - 0x%"PRIx64
-- 
2.31.1