diff mbox series

[RFC,v6,42/92] KVM: MMU: Handle host memory remapping and reclaim

Message ID 20190809160047.8319-43-alazar@bitdefender.com (mailing list archive)
State New, archived
Headers show
Series VM introspection | expand

Commit Message

Adalbert Lazăr Aug. 9, 2019, 3:59 p.m. UTC 
From: Yang Weijiang <weijiang.yang@intel.com>

Host page swapping/migration may change the translation in
EPT leaf entry, if the target page is SPP protected,
re-enable SPP protection in MMU notifier. If SPPT shadow
page is reclaimed, the level1 pages don't have rmap to clear.

Signed-off-by: Yang Weijiang <weijiang.yang@intel.com>
Message-Id: <20190717133751.12910-10-weijiang.yang@intel.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 arch/x86/kvm/mmu.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)
diff mbox series

Patch

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 24222e3add91..0b859b1797f6 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -2004,6 +2004,24 @@  static int kvm_set_pte_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head,
 			new_spte &= ~PT_WRITABLE_MASK;
 			new_spte &= ~SPTE_HOST_WRITEABLE;
 
+			/*
+			 * if it's EPT leaf entry and the physical page is
+			 * SPP protected, then re-enable SPP protection for
+			 * the page.
+			 */
+			if (kvm->arch.spp_active &&
+			    level == PT_PAGE_TABLE_LEVEL) {
+				struct kvm_subpage spp_info = {0};
+				int i;
+
+				spp_info.base_gfn = gfn;
+				spp_info.npages = 1;
+				i = kvm_mmu_get_subpages(kvm, &spp_info, true);
+				if (i == 1 &&
+				    spp_info.access_map[0] != FULL_SPP_ACCESS)
+					new_spte |= PT_SPP_MASK;
+			}
+
 			new_spte = mark_spte_for_access_track(new_spte);
 
 			mmu_spte_clear_track_bits(sptep);
@@ -2905,6 +2923,10 @@  static bool mmu_page_zap_pte(struct kvm *kvm, struct kvm_mmu_page *sp,
 	pte = *spte;
 	if (is_shadow_present_pte(pte)) {
 		if (is_last_spte(pte, sp->role.level)) {
+			/* SPPT leaf entries don't have rmaps*/
+			if (sp->role.level == PT_PAGE_TABLE_LEVEL &&
+			    is_spp_spte(sp))
+				return true;
 			drop_spte(kvm, spte);
 			if (is_large_pte(pte))
 				--kvm->stat.lpages;