Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754716AbdLFKAZ (ORCPT ); Wed, 6 Dec 2017 05:00:25 -0500 Received: from mx1.redhat.com ([209.132.183.28]:37656 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751961AbdLFKAV (ORCPT ); Wed, 6 Dec 2017 05:00:21 -0500 Subject: Re: [PATCH 1/2] KVM: x86: fix APIC page invalidation To: =?UTF-8?B?546L6YeR5rWm?= , Wanpeng Li , =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= Cc: =?UTF-8?Q?Fabian_Gr=c3=bcnbichler?= , "linux-kernel@vger.kernel.org" , linux-mm , kvm , Andrea Arcangeli , =?UTF-8?B?SsOpcsO0bWUgR2xpc3Nl?= References: <20171130161933.GB1606@flask> <20171130180546.4331-1-rkrcmar@redhat.com> From: Paolo Bonzini Message-ID: <0b267ec6-0baa-75cc-4686-79bd6ebf3468@redhat.com> Date: Wed, 6 Dec 2017 11:00:16 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.4.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.31]); Wed, 06 Dec 2017 10:00:21 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4036 Lines: 107 On 06/12/2017 10:50, 王金浦 wrote: > 2017-12-06 3:32 GMT+01:00 Wanpeng Li : >> 2017-12-01 2:05 GMT+08:00 Radim Krčmář : >>> 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 > So the patch should be backport to v3.18+? In practice the invalidate_page callback was enough because the APIC page is allocated with alloc_page(). But it doesn't hurt. Paolo > Thanks, > Jack >> >> Tested-by: Wanpeng Li >> >> I observe the windows 2016 guest hang during boot on a heavy memory >> overcommit host, and this commit fixes it. >> >> Regards, >> Wanpeng Li >> >>> --- >>> 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 >>> >>> -- >>> To unsubscribe, send a message with 'unsubscribe linux-mm' in >>> the body to majordomo@kvack.org. For more info on Linux MM, >>> see: http://www.linux-mm.org/ . >>> Don't email: email@kvack.org