Accelerated SMMUv3 instances rely on the physical SMMUv3 for nested translation (guest Stage-1, host Stage-2). In this mode, the guest Stage-1 tables are programmed directly into hardware, and QEMU must not attempt to walk them for translation, as doing so is not reliably safe. For vfio-pci endpoints behind such a vSMMU, the only translation QEMU needs to perform is for the MSI doorbell used during KVM MSI setup.
Implement the callback so that kvm_arch_fixup_msi_route() can retrieve the MSI doorbell GPA directly, instead of attempting a software walk of the guest translation tables. Also introduce an SMMUv3 device property to carry the MSI doorbell GPA. This property will be set by the virt machine in a subsequent patch. Reviewed-by: Nicolin Chen <[email protected]> Signed-off-by: Shameer Kolothum <[email protected]> --- hw/arm/smmuv3-accel.c | 10 ++++++++++ hw/arm/smmuv3.c | 2 ++ include/hw/arm/smmuv3.h | 1 + 3 files changed, 13 insertions(+) diff --git a/hw/arm/smmuv3-accel.c b/hw/arm/smmuv3-accel.c index c125974d12..c6ee123cdf 100644 --- a/hw/arm/smmuv3-accel.c +++ b/hw/arm/smmuv3-accel.c @@ -393,6 +393,15 @@ static void smmuv3_accel_unset_iommu_device(PCIBus *bus, void *opaque, } } +static uint64_t smmuv3_accel_get_msi_gpa(PCIBus *bus, void *opaque, int devfn) +{ + SMMUState *bs = opaque; + SMMUv3State *s = ARM_SMMUV3(bs); + + g_assert(s->msi_gpa); + return s->msi_gpa; +} + /* * Only allow PCIe bridges, pxb-pcie roots, and GPEX roots so vfio-pci * endpoints can sit downstream. Accelerated SMMUv3 requires a vfio-pci @@ -497,6 +506,7 @@ static const PCIIOMMUOps smmuv3_accel_ops = { .get_viommu_flags = smmuv3_accel_get_viommu_flags, .set_iommu_device = smmuv3_accel_set_iommu_device, .unset_iommu_device = smmuv3_accel_unset_iommu_device, + .get_msi_direct_gpa = smmuv3_accel_get_msi_gpa, }; /* Based on SMUUv3 GPBA.ABORT configuration, attach a corresponding HWPT */ diff --git a/hw/arm/smmuv3.c b/hw/arm/smmuv3.c index 7a32afd800..6ed9914b1e 100644 --- a/hw/arm/smmuv3.c +++ b/hw/arm/smmuv3.c @@ -1998,6 +1998,8 @@ static const Property smmuv3_properties[] = { * Defaults to stage 1 */ DEFINE_PROP_STRING("stage", SMMUv3State, stage), + /* GPA of MSI doorbell, for SMMUv3 accel use. */ + DEFINE_PROP_UINT64("msi-gpa", SMMUv3State, msi_gpa, 0), }; static void smmuv3_instance_init(Object *obj) diff --git a/include/hw/arm/smmuv3.h b/include/hw/arm/smmuv3.h index e54ece2d38..5616a8a2be 100644 --- a/include/hw/arm/smmuv3.h +++ b/include/hw/arm/smmuv3.h @@ -67,6 +67,7 @@ struct SMMUv3State { /* SMMU has HW accelerator support for nested S1 + s2 */ bool accel; struct SMMUv3AccelState *s_accel; + uint64_t msi_gpa; }; typedef enum { -- 2.43.0
