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Patch "KVM: x86: fix APIC page invalidation" has been added to the 4.9-stable tree

PATCH [email protected] 1 participant 1 message Dec 11, 2017

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This is a note to let you know that I've just added the patch titled

KVM: x86: fix APIC page invalidation

to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
kvm-x86-fix-apic-page-invalidation.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

Quoted 1 line

From b1394e745b9453dcb5b0671c205b770e87dedb87 Mon Sep 17 00:00:00 2001

From: =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= <[email protected]>
Date: Thu, 30 Nov 2017 19:05:45 +0100
Subject: KVM: x86: fix APIC page invalidation
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
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From: Radim Krčmář <[email protected]>

commit b1394e745b9453dcb5b0671c205b770e87dedb87 upstream.

Implementation of the unpinned APIC page didn't update the VMCS address cache when invalidation was done through range mmu notifiers. This became a problem when the page notifier was removed.

Re-introduce the arch-specific helper and call it from ...range_start.

Reported-by Fabian Grünbichler <[email protected]>
Fixes 38b9917350cb ("kvm: vmx: Implement set_apic_access_page_addr")
Fixes 369ea8242c0f ("mm/rmap: update to new mmu_notifier semantic v2")
Reviewed-by Paolo Bonzini <[email protected]>
Reviewed-by Andrea Arcangeli <[email protected]>
Tested-by Wanpeng Li <[email protected]>
Tested-by Fabian Grünbichler <[email protected]>
Signed-off-by Radim Krčmář <[email protected]>
Signed-off-by Greg Kroah-Hartman <[email protected]>
---
 arch/x86/include/asm/kvm_host.h |    3 +++
 arch/x86/kvm/x86.c              |   14 ++++++++++++++
 virt/kvm/kvm_main.c             |    8 ++++++++
 3 files changed, 25 insertions(+)
arch/x86/include/asm/kvm_host.h +3 -0
@@ -1397,4 +1397,7 @@ static inline int kvm_cpu_get_apicid(int
 #endif
 }
 
+void kvm_arch_mmu_notifier_invalidate_range(struct kvm *kvm,
+		unsigned long start, unsigned long end);
+
 #endif /* _ASM_X86_KVM_HOST_H */
arch/x86/kvm/x86.c +14 -0
@@ -6526,6 +6526,20 @@ static void kvm_vcpu_flush_tlb(struct kv
 	kvm_x86_ops->tlb_flush(vcpu);
 }
 
+void kvm_arch_mmu_notifier_invalidate_range(struct kvm *kvm,
+		unsigned long start, unsigned long end)
+{
+	unsigned long apic_address;
+
+	/*
+	 * The physical address of apic access page is stored in the VMCS.
+	 * Update it when it becomes invalid.
+	 */
+	apic_address = gfn_to_hva(kvm, APIC_DEFAULT_PHYS_BASE >> PAGE_SHIFT);
+	if (start <= apic_address && apic_address < end)
+		kvm_make_all_cpus_request(kvm, KVM_REQ_APIC_PAGE_RELOAD);
+}
+
 void kvm_vcpu_reload_apic_access_page(struct kvm_vcpu *vcpu)
 {
 	struct page *page = NULL;
virt/kvm/kvm_main.c +8 -0
@@ -125,6 +125,11 @@ EXPORT_SYMBOL_GPL(kvm_rebooting);
 
 static bool largepages_enabled = true;
 
+__weak void kvm_arch_mmu_notifier_invalidate_range(struct kvm *kvm,
+		unsigned long start, unsigned long end)
+{
+}
+
 bool kvm_is_reserved_pfn(kvm_pfn_t pfn)
 {
 	if (pfn_valid(pfn))

@@ -361,6 +366,9 @@ static void kvm_mmu_notifier_invalidate_
 		kvm_flush_remote_tlbs(kvm);
 
 	spin_unlock(&kvm->mmu_lock);
+
+	kvm_arch_mmu_notifier_invalidate_range(kvm, start, end);
+
 	srcu_read_unlock(&kvm->srcu, idx);
 }

Patches currently in stable-queue which might be from [email protected] are

queue-4.9/kvm-vmx-remove-i-o-port-0x80-bypass-on-intel-hosts.patch queue-4.9/kvm-x86-fix-apic-page-invalidation.patch