amd_iommu: Fix the calculation for Device Table size

Correctly calculate the Device Table size using the format encoded in the
Device Table Base Address Register (MMIO Offset 0000h).

Cc: qemu-stable@nongnu.org
Fixes: d29a09ca6842 ("hw/i386: Introduce AMD IOMMU")
Signed-off-by: Alejandro Jimenez <alejandro.j.jimenez@oracle.com>
Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>
Message-Id: <20250617150427.20585-7-alejandro.j.jimenez@oracle.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
(cherry picked from commit 67d3077ee403472d45794399e97c9f329242fce9)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

diff --git a/hw/i386/amd_iommu.c b/hw/i386/amd_iommu.c
index f2da6348f659d94fd7a2b41fdd02b568a5bd2155..0df9c1a2323624819f1b9be4aa5ce16d45f3117c 100644 (file)
--- a/hw/i386/amd_iommu.c
+++ b/hw/i386/amd_iommu.c
@@ -640,8 +640,8 @@ static inline void amdvi_handle_devtab_write(AMDVIState *s)
     uint64_t val = amdvi_readq(s, AMDVI_MMIO_DEVICE_TABLE);
     s->devtab = (val & AMDVI_MMIO_DEVTAB_BASE_MASK);
 
-    /* set device table length */
-    s->devtab_len = ((val & AMDVI_MMIO_DEVTAB_SIZE_MASK) + 1 *
+    /* set device table length (i.e. number of entries table can hold) */
+    s->devtab_len = (((val & AMDVI_MMIO_DEVTAB_SIZE_MASK) + 1) *
                     (AMDVI_MMIO_DEVTAB_SIZE_UNIT /
                      AMDVI_MMIO_DEVTAB_ENTRY_SIZE));
 }