Re: [RFC PATCH v12 02/33] KVM: Use gfn instead of hva for mmu_notifier_retry
flat view
From: Sean Christopherson <seanjc@google.com>
Date: 2023-09-20 13:56:05
Also in:
kvm, kvm-riscv, kvmarm, linux-arm-kernel, linux-fsdevel, linux-mips, linux-mm, linux-riscv, linux-security-module, lkml
On Wed, Sep 20, 2023, Xu Yilun wrote:
On 2023-09-13 at 18:55:00 -0700, Sean Christopherson wrote:quoted
+void kvm_mmu_invalidate_range_add(struct kvm *kvm, gfn_t start, gfn_t end) +{ + lockdep_assert_held_write(&kvm->mmu_lock); + + WARN_ON_ONCE(!kvm->mmu_invalidate_in_progress); + if (likely(kvm->mmu_invalidate_in_progress == 1)) { kvm->mmu_invalidate_range_start = start; kvm->mmu_invalidate_range_end = end;IIUC, Now we only add or override a part of the invalidate range in these fields, IOW only the range in last slot is stored when we unlock.
Ouch. Good catch!
That may break mmu_invalidate_retry_gfn() cause it can never know the
whole invalidate range.
How about we extend the mmu_invalidate_range_start/end everytime so that
it records the whole invalidate range:
if (kvm->mmu_invalidate_range_start == INVALID_GPA) {
kvm->mmu_invalidate_range_start = start;
kvm->mmu_invalidate_range_end = end;
} else {
kvm->mmu_invalidate_range_start =
min(kvm->mmu_invalidate_range_start, start);
kvm->mmu_invalidate_range_end =
max(kvm->mmu_invalidate_range_end, end);
}Yeah, that does seem to be the easiest solution. I'll post a fixup patch, unless you want the honors.