On 4/22/25 8:26 AM, Sairaj Kodilkar wrote:
On 4/14/2025 7:32 AM, Alejandro Jimenez wrote:
The size of the region to invalidate depends on the S bit and address
encoded in the command. Add a helper to extract this information, which
will be used to sync shadow page tables in upcoming changes.
Signed-off-by: Alejandro Jimenez <alejandro.j.jime...@oracle.com>
---
hw/i386/amd_iommu.c | 34 ++++++++++++++++++++++++++++++++++
hw/i386/amd_iommu.h | 4 ++++
2 files changed, 38 insertions(+)
diff --git a/hw/i386/amd_iommu.c b/hw/i386/amd_iommu.c
index 5f55be1f4d36..0af873b66a31 100644
--- a/hw/i386/amd_iommu.c
+++ b/hw/i386/amd_iommu.c
+static uint64_t __attribute__((unused))
+amdvi_decode_invalidation_size(hwaddr addr, uint16_t flags)
+{
+ uint64_t size = AMDVI_PAGE_SIZE;
+ uint8_t fzbit = 0;
+
+ if (flags & AMDVI_CMD_INVAL_IOMMU_PAGES_S) {
+ fzbit = cto64(addr | 0xFFF);
+
+ if (fzbit >= 51 || !addr) {
I am skeptical about the condition addr == 0 (!addr)
Consider the case where user wants to invalidate 8K size page, starting
from address 0. It'll cause address field to be 0, right ? If so, then
we should invalidate only 8K page not the entire address range.
You are right, I'll fix the issue (i.e. remove the !addr special case)
in v2.
This was a remnant of an earlier prototype where I was decoding the
address with a different method, but as you point out this special case
is not needed anymore and would result in sub-optimal behavior.
Thank you!
Alejandro
Am I missing something here ?
Regards
Sairaj
