[PATCH 10/14] KVM: x86/mmu: Remove obsolete gfn restoration in FNAME(fetch)

Sean Christopherson
2020-01-08T20:27:32Z

Remove logic to retrieve the original gfn now that HugeTLB mappings are
are identified in FNAME(fetch), i.e. FNAME(page_fault) no longer adjusts
the level or gfn.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
arch/x86/kvm/mmu/paging_tmpl.h | 13 +++----------
1 file changed, 3 insertions(+), 10 deletions(-)

diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h
index 841506a55815..0560982eda8b 100644
--- a/arch/x86/kvm/mmu/paging_tmpl.h
+++ b/arch/x86/kvm/mmu/paging_tmpl.h
@@ -621,7 +621,7 @@ static int FNAME(fetch)(struct kvm_vcpu *vcpu, gpa_t addr,
struct kvm_shadow_walk_iterator it;
unsigned direct_access, access = gw->pt_access;
int top_level, hlevel, ret;
- gfn_t gfn, base_gfn;
+ gfn_t base_gfn = gw->gfn;

direct_access = gw->pte_access;

@@ -666,13 +666,6 @@ static int FNAME(fetch)(struct kvm_vcpu *vcpu, gpa_t addr,
link_shadow_page(vcpu, it.sptep, sp);
}

- /*
- * FNAME(page_fault) might have clobbered the bottom bits of
- * gw->gfn, restore them from the virtual address.
- */
- gfn = gw->gfn | ((addr & PT_LVL_OFFSET_MASK(gw->level)) >> PAGE_SHIFT);
- base_gfn = gfn;
-
hlevel = kvm_mmu_hugepage_adjust(vcpu, gw->gfn, max_level, &pfn);

trace_kvm_mmu_spte_requested(addr, gw->level, pfn);
@@ -684,9 +677,9 @@ static int FNAME(fetch)(struct kvm_vcpu *vcpu, gpa_t addr,
* We cannot overwrite existing page tables with an NX
* large page, as the leaf could be executable.
*/
- disallowed_hugepage_adjust(it, gfn, &pfn, &hlevel);
+ disallowed_hugepage_adjust(it, gw->gfn, &pfn, &hlevel);

- base_gfn = gfn & ~(KVM_PAGES_PER_HPAGE(it.level) - 1);
+ base_gfn = gw->gfn & ~(KVM_PAGES_PER_HPAGE(it.level) - 1);
if (it.level == hlevel)
break;

--
2.24.1