Clean up KVM's PV TLB flushing when running with EPT on Hyper-V, i.e. as
a nested VMM. No real goal in mind other than the sole patch in v1, which
is a minor change to avoid a future mixup when TDX also wants to define
.remote_flush_tlb. Everything else is opportunistic clean up.
NOTE: Based on my NPT+SME bug fix series[*] due to multiple conflicts with
non-trivial resolutions.
[*] https://lkml.kernel.org/r/20210305011101.3597423-1-seanjc@xxxxxxxxxx
Patch 1 legitimately tested on VMX and SVM (including i386). Patches 2+
smoke tested by hacking usage of the relevant flows without actually
routing to the Hyper-V hypercalls (partial hack-a-patch below).
-static inline int hv_remote_flush_root_ept(hpa_t root_ept,
+static inline int hv_remote_flush_root_ept(struct kvm *kvm, hpa_t root_ept,
struct kvm_tlb_range *range)
{
- if (range)
- return hyperv_flush_guest_mapping_range(root_ept,
- kvm_fill_hv_flush_list_func, (void *)range);
- else
- return hyperv_flush_guest_mapping(root_ept);
+ if (range) {
+ kvm_make_all_cpus_request(kvm, KVM_REQ_TLB_FLUSH);
+ return 0;
+ }
+
+ return -ENOMEM;
}
static int hv_remote_flush_tlb_with_range(struct kvm *kvm,
@@ -7753,8 +7754,7 @@ static __init int hardware_setup(void)
vmx_x86_ops.update_cr8_intercept = NULL;
#if IS_ENABLED(CONFIG_HYPERV)
- if (ms_hyperv.nested_features & HV_X64_NESTED_GUEST_MAPPING_FLUSH
- && enable_ept) {
+ if (enable_ept) {
vmx_x86_ops.tlb_remote_flush = hv_remote_flush_tlb;
vmx_x86_ops.tlb_remote_flush_with_range =
hv_remote_flush_tlb_with_range;
v4:
- Rebased to kvm/queue, commit fe5f0041c026 ("KVM/SVM: Move vmenter.S
exception fixups out of line"), plus the aforementioned series.
- Don't grab PCID for nested_cr3 (NPT). [Paolo]
- Collect reviews. [Vitaly]
v3:
- https://lkml.kernel.org/r/20201027212346.23409-1-sean.j.christopherson@xxxxxxxxx
- Add a patch to pass the root_hpa instead of pgd to vmx_load_mmu_pgd()
and retrieve the active PCID only when necessary. [Vitaly]
- Selectively collects reviews (skipped a few due to changes). [Vitaly]
- Explicitly invalidate hv_tlb_eptp instead of leaving it valid when
the mismatch tracker "knows" it's invalid. [Vitaly]
- Change the last patch to use "hv_root_ept" instead of "hv_tlb_pgd"
to better reflect what is actually being tracked.
v2:
- Rewrite everything.
- https://lkml.kernel.org/r/20201020215613.8972-1-sean.j.christopherson@xxxxxxxxx
v1: ???
Sean Christopherson (11):
KVM: x86: Get active PCID only when writing a CR3 value
KVM: VMX: Track common EPTP for Hyper-V's paravirt TLB flush
KVM: VMX: Stash kvm_vmx in a local variable for Hyper-V paravirt TLB
flush
KVM: VMX: Fold Hyper-V EPTP checking into it's only caller
KVM: VMX: Do Hyper-V TLB flush iff vCPU's EPTP hasn't been flushed
KVM: VMX: Invalidate hv_tlb_eptp to denote an EPTP mismatch
KVM: VMX: Don't invalidate hv_tlb_eptp if the new EPTP matches
KVM: VMX: Explicitly check for hv_remote_flush_tlb when loading pgd
KVM: VMX: Define Hyper-V paravirt TLB flush fields iff Hyper-V is
enabled
KVM: VMX: Skip additional Hyper-V TLB EPTP flushes if one fails
KVM: VMX: Track root HPA instead of EPTP for paravirt Hyper-V TLB
flush
arch/x86/include/asm/kvm_host.h | 4 +-
arch/x86/kvm/mmu.h | 4 +-
arch/x86/kvm/svm/svm.c | 10 ++-
arch/x86/kvm/vmx/vmx.c | 134 ++++++++++++++++++--------------
arch/x86/kvm/vmx/vmx.h | 19 ++---
5 files changed, 92 insertions(+), 79 deletions(-)
--
2.30.1.766.gb4fecdf3b7-goog
