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From: Yang Weijiang <weijiang.yang@intel.com>
To: kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
	pbonzini@redhat.com, jmattson@google.com,
	sean.j.christopherson@intel.com
Cc: yu.c.zhang@linux.intel.com, alazar@bitdefender.com,
	edwin.zhai@intel.com, Yang Weijiang <weijiang.yang@intel.com>
Subject: [PATCH v8 08/10] mmu: spp: Handle SPP protected pages when VM memory changes
Date: Sat, 30 Nov 2019 01:27:07 +0800
Message-ID: <20191129172709.11347-9-weijiang.yang@intel.com> (raw)
In-Reply-To: <20191129172709.11347-1-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>
---
 arch/x86/kvm/mmu/mmu.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 2a407c74427d..410ddc234b46 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -1828,6 +1828,19 @@ 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) {
+				u32 *access = gfn_to_subpage_wp_info(slot, gfn);
+
+				if (access && *access != FULL_SPP_ACCESS)
+					new_spte |= PT_SPP_MASK;
+			}
+
 			new_spte = mark_spte_for_access_track(new_spte);
 
 			mmu_spte_clear_track_bits(sptep);
@@ -2677,6 +2690,10 @@ 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;
-- 
2.17.2


  parent reply index

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-11-29 17:26 [PATCH v8 00/10] Enable Sub-Page Write Protection Support Yang Weijiang
2019-11-29 17:27 ` [PATCH v8 01/10] Documentation: Introduce EPT based Subpage Protection and related APIs Yang Weijiang
2019-11-29 17:27 ` [PATCH v8 02/10] vmx: spp: Add control flags for Sub-Page Protection(SPP) Yang Weijiang
2019-11-29 17:27 ` [PATCH v8 03/10] mmu: spp: Add SPP Table setup functions Yang Weijiang
2019-11-29 17:27 ` [PATCH v8 04/10] mmu: spp: Add functions to operate SPP access bitmap Yang Weijiang
2019-11-29 17:27 ` [PATCH v8 05/10] x86: spp: Introduce user-space SPP IOCTLs Yang Weijiang
2019-11-29 17:27 ` [PATCH v8 06/10] vmx: spp: Set up SPP paging table at vmentry/vmexit Yang Weijiang
2019-11-29 17:27 ` [PATCH v8 07/10] mmu: spp: Enable Lazy mode SPP protection Yang Weijiang
2019-11-29 17:27 ` Yang Weijiang [this message]
2019-11-29 17:27 ` [PATCH v8 09/10] x86: spp: Add SPP protection check in emulation Yang Weijiang
2019-11-29 17:27 ` [PATCH v8 10/10] kvm: selftests: selftest for Sub-Page protection Yang Weijiang

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