On 5/2/2025 7:45 AM, Alejandro Jimenez wrote:
Extracting the DTE from a given AMDVIAddressSpace pointer structure is a
common operation required for syncing the shadow page tables. Implement a
helper to do it and check for common error conditions.
Signed-off-by: Alejandro Jimenez <alejandro.j.jime...@oracle.com>
---
hw/i386/amd_iommu.c | 45 ++++++++++++++++++++++++++++++++++++++++-----
1 file changed, 40 insertions(+), 5 deletions(-)
diff --git a/hw/i386/amd_iommu.c b/hw/i386/amd_iommu.c
index dff6f04c8651..5322a614f5d6 100644
--- a/hw/i386/amd_iommu.c
+++ b/hw/i386/amd_iommu.c
@@ -77,6 +77,18 @@ typedef struct AMDVIIOTLBEntry {
uint64_t page_mask; /* physical page size */
} AMDVIIOTLBEntry;
+/*
+ * These 'fault' reasons have an overloaded meaning since they are not only
+ * intended for describing reasons that generate an IO_PAGE_FAULT as per the
AMD
+ * IOMMU specification, but are also used to signal internal errors in the
+ * emulation code.
+ */
+typedef enum AMDVIFaultReason {
+ AMDVI_FR_DTE_RTR_ERR = 1, /* Failure to retrieve DTE */
+ AMDVI_FR_DTE_V, /* DTE[V] = 0 */
+ AMDVI_FR_DTE_TV, /* DTE[TV] = 0 */
+} AMDVIFaultReason;
+
uint64_t amdvi_extended_feature_register(AMDVIState *s)
{
uint64_t feature = AMDVI_DEFAULT_EXT_FEATURES;
@@ -492,6 +504,28 @@ static inline uint64_t amdvi_get_pte_entry(AMDVIState *s,
uint64_t pte_addr,
return pte;
}
+static int amdvi_as_to_dte(AMDVIAddressSpace *as, uint64_t *dte)
+{
+ uint16_t devid = PCI_BUILD_BDF(as->bus_num, as->devfn);
+ AMDVIState *s = as->iommu_state;
+
+ if (!amdvi_get_dte(s, devid, dte)) {
+ /* Unable to retrieve DTE for devid */
+ return -AMDVI_FR_DTE_RTR_ERR;
+ }
+
+ if (!(dte[0] & AMDVI_DEV_VALID)) {
+ /* DTE[V] not set, address is passed untranslated for devid */
+ return -AMDVI_FR_DTE_V;
+ }
+
+ if (!(dte[0] & AMDVI_DEV_TRANSLATION_VALID)) {
+ /* DTE[TV] not set, host page table not valid for devid */
+ return -AMDVI_FR_DTE_TV;
+ }
+ return 0;
+}
+
/* log error without aborting since linux seems to be using reserved bits */
static void amdvi_inval_devtab_entry(AMDVIState *s, uint64_t *cmd)
{
@@ -1024,6 +1058,7 @@ static void amdvi_do_translate(AMDVIAddressSpace *as,
hwaddr addr,
uint16_t devid = PCI_BUILD_BDF(as->bus_num, as->devfn);
AMDVIIOTLBEntry *iotlb_entry = amdvi_iotlb_lookup(s, addr, devid);
uint64_t entry[4];
+ int dte_ret;
if (iotlb_entry) {
trace_amdvi_iotlb_hit(PCI_BUS_NUM(devid), PCI_SLOT(devid),
@@ -1035,13 +1070,13 @@ static void amdvi_do_translate(AMDVIAddressSpace *as,
hwaddr addr,
return;
}
- if (!amdvi_get_dte(s, devid, entry)) {
- return;
- }
+ dte_ret = amdvi_as_to_dte(as, entry);
- /* devices with V = 0 are not translated */
- if (!(entry[0] & AMDVI_DEV_VALID)) {
+ if (dte_ret == -AMDVI_FR_DTE_V) {
+ /* DTE[V]=0, address is passed untranslated */
goto out;
+ } else if (dte_ret == -AMDVI_FR_DTE_TV) {
+ return;
}
Hi Alejandro,
You missed to handle -AMDVI_FR_DTE_RTR_ERR.
Regards
Sairaj Kodilkar
amdvi_page_walk(as, entry, ret,
