2017-11-30 12:20+0100, Paolo Bonzini:
> On 30/11/2017 10:33, Fabian Grünbichler wrote:
> >
> > It was reverted in 785373b4c38719f4af6775845df6be1dfaea120f after which
> > the symptoms disappeared until this series was merged, which contains
> >
> > 369ea8242c0fb5239b4ddf0dc568f694bd244de4 mm/rmap: update to new mmu_notifier semantic v2
> >
> > We haven't bisected the individual commits of the series yet, but the
> > commit immediately preceding its merge exhibits no problems, while
> > everything after does. It is not known whether the bug is actually in
> > the series itself, or whether increasing the likelihood of triggering it
> > is just a side-effect. There is a similar report[2] concerning an
> > upgrade from 4.12.12 to 4.12.13, which does not contain this series in
> > any form AFAICT but might be worth another look as well.
>
> I know of one issue in this series (invalidate_page was removed from KVM
> without reimplementing it as invalidate_range). I'll try to prioritize
> the fix, but I don't think I can do it before Monday.
The series also dropped the reloading of the APIC access page and we
never had it in invalidate_range_start ... I'll look into it today.
From 1585489780539456462@xxx Thu Nov 30 11:21:22 +0000 2017
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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.
Fixes: 38b9917350cb ("kvm: vmx: Implement set_apic_access_page_addr")
Fixes: 369ea8242c0f ("mm/rmap: update to new mmu_notifier semantic v2")
Signed-off-by: Radim Krčmář <[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(+)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 977de5fb968b..c16c3f924863 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1435,4 +1435,7 @@ static inline int kvm_cpu_get_apicid(int mps_cpu)
#define put_smstate(type, buf, offset, val) \
*(type *)((buf) + (offset) - 0x7e00) = val
+void kvm_arch_mmu_notifier_invalidate_range(struct kvm *kvm,
+ unsigned long start, unsigned long end);
+
#endif /* _ASM_X86_KVM_HOST_H */
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index eee8e7faf1af..a219974cdb89 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6778,6 +6778,20 @@ static void kvm_vcpu_flush_tlb(struct kvm_vcpu *vcpu)
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;
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index c01cff064ec5..b7f4689e373f 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -135,6 +135,11 @@ static void kvm_uevent_notify_change(unsigned int type, struct kvm *kvm);
static unsigned long long kvm_createvm_count;
static unsigned long long kvm_active_vms;
+__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))
@@ -360,6 +365,9 @@ static void kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn,
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);
}
--
2.14.2
From 1585229288716126163@xxx Mon Nov 27 14:20:58 +0000 2017
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