Re: [PATCH 07/21] KVM: x86/mmu: Topup memory caches after walking GVA->GPA
From: Ben Gardon <hidden>
Date: 2020-06-10 22:34:43
Also in:
kvm, kvmarm, linux-mips, lkml
On Fri, Jun 5, 2020 at 2:39 PM Sean Christopherson [off-list ref] wrote:
Topup memory caches after walking the GVA->GPA translation during a
shadow page fault, there is no need to ensure the caches are full when
walking the GVA. As of commit f5a1e9f89504f ("KVM: MMU: remove call
to kvm_mmu_pte_write from walk_addr"), the FNAME(walk_addr) flow no
longer add rmaps via kvm_mmu_pte_write().
This avoids allocating memory in the case that the GVA is unmapped in
the guest, and also provides a paper trail of why/when the memory caches
need to be filled.
Signed-off-by: Sean Christopherson <redacted>Reviewed-by: Ben Gardon <redacted>
quoted hunk ↗ jump to hunk
--- arch/x86/kvm/mmu/paging_tmpl.h | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h index 38c576495048..3de32122f601 100644 --- a/arch/x86/kvm/mmu/paging_tmpl.h +++ b/arch/x86/kvm/mmu/paging_tmpl.h@@ -791,10 +791,6 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gpa_t addr, u32 error_code, pgprintk("%s: addr %lx err %x\n", __func__, addr, error_code); - r = mmu_topup_memory_caches(vcpu); - if (r) - return r; - /* * If PFEC.RSVD is set, this is a shadow page fault. * The bit needs to be cleared before walking guest page tables.@@ -822,6 +818,10 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gpa_t addr, u32 error_code, return RET_PF_EMULATE; } + r = mmu_topup_memory_caches(vcpu); + if (r) + return r; + vcpu->arch.write_fault_to_shadow_pgtable = false; is_self_change_mapping = FNAME(is_self_change_mapping)(vcpu, --2.26.0
_______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel