From: Zhenzhong Duan <[email protected]> According to VTD spec rev 4.1 section 6.6: "For implementations reporting the Enhanced Set Root Table Pointer Support (ESRTPS) field as Clear, on a 'Set Root Table Pointer' operation, software must perform a global invalidate of the context cache, PASID-cache (if applicable), and IOTLB, in that order. This is required to ensure hardware references only the remapping structures referenced by the new root table pointer and not stale cached entries.
For implementations reporting the Enhanced Set Root Table Pointer Support (ESRTPS) field as Set, as part of 'Set Root Table Pointer' operation, hardware performs global invalidation on all DMA remapping translation caches and hence software is not required to perform additional invalidations" We already implemented ESRTPS capability in vtd_handle_gcmd_srtp() by calling vtd_reset_caches(), just set ESRTPS in DMAR_CAP_REG to avoid unnecessary global invalidation requests of context, PASID-cache and IOTLB from guest. This change doesn't impact migration as the content of DMAR_CAP_REG is migrated too. Signed-off-by: Zhenzhong Duan <[email protected]> Reviewed-by: Clément Mathieu--Drif <[email protected]> Reviewed-by: Michael S. Tsirkin <[email protected]> Message-ID: <[email protected]> Signed-off-by: Michael S. Tsirkin <[email protected]> --- hw/i386/intel_iommu_internal.h | 1 + hw/i386/intel_iommu.c | 2 +- 2 files changed, 2 insertions(+), 1 deletion(-) diff --git a/hw/i386/intel_iommu_internal.h b/hw/i386/intel_iommu_internal.h index 0d0069a612..0f6a1237e4 100644 --- a/hw/i386/intel_iommu_internal.h +++ b/hw/i386/intel_iommu_internal.h @@ -215,6 +215,7 @@ #define VTD_CAP_DRAIN_WRITE (1ULL << 54) #define VTD_CAP_DRAIN_READ (1ULL << 55) #define VTD_CAP_FS1GP (1ULL << 56) +#define VTD_CAP_ESRTPS (1ULL << 63) #define VTD_CAP_DRAIN (VTD_CAP_DRAIN_READ | VTD_CAP_DRAIN_WRITE) #define VTD_CAP_CM (1ULL << 7) #define VTD_PASID_ID_SHIFT 20 diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c index fa2ad9c2eb..0378551038 100644 --- a/hw/i386/intel_iommu.c +++ b/hw/i386/intel_iommu.c @@ -4660,7 +4660,7 @@ static void vtd_cap_init(IntelIOMMUState *s) s->cap = VTD_CAP_FRO | VTD_CAP_NFR | VTD_CAP_ND | VTD_CAP_MAMV | VTD_CAP_PSI | VTD_CAP_SLLPS | - VTD_CAP_MGAW(s->aw_bits); + VTD_CAP_ESRTPS | VTD_CAP_MGAW(s->aw_bits); if (s->dma_drain) { s->cap |= VTD_CAP_DRAIN; } -- MST
