From: Janosch Frank <frankja@linux.ibm.com>
To: Sean Christopherson <seanjc@google.com>,
Paolo Bonzini <pbonzini@redhat.com>,
Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: David Hildenbrand <david@redhat.com>,
Claudio Imbrenda <imbrenda@linux.ibm.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
Wanpeng Li <wanpengli@tencent.com>,
Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
Maxim Levitsky <mlevitsk@redhat.com>,
Ben Gardon <bgardon@google.com>,
Lai Jiangshan <jiangshanlai@gmail.com>
Subject: Re: [PATCH 5/7] KVM: s390: Replace KVM_REQ_MMU_RELOAD usage with arch specific request
Date: Thu, 9 Dec 2021 11:52:30 +0100 [thread overview]
Message-ID: <24c84413-4965-9105-fc02-2f72ab053b2a@linux.ibm.com> (raw)
In-Reply-To: <20211209060552.2956723-6-seanjc@google.com>
On 12/9/21 07:05, Sean Christopherson wrote:
> Add an arch request, KVM_REQ_REFRESH_GUEST_PREFIX, to deal with guest
> prefix changes instead of piggybacking KVM_REQ_MMU_RELOAD. This will
> allow for the removal of the generic KVM_REQ_MMU_RELOAD, which isn't
> actually used by generic KVM.
Yes, that does sound nicer.
>
> No functional change intended.
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
>
> Signed-off-by: Sean Christopherson <seanjc@google.com>
> ---
> arch/s390/include/asm/kvm_host.h | 2 ++
> arch/s390/kvm/kvm-s390.c | 8 ++++----
> arch/s390/kvm/kvm-s390.h | 2 +-
> 3 files changed, 7 insertions(+), 5 deletions(-)
>
> diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
> index a22c9266ea05..766028d54a3e 100644
> --- a/arch/s390/include/asm/kvm_host.h
> +++ b/arch/s390/include/asm/kvm_host.h
> @@ -45,6 +45,8 @@
> #define KVM_REQ_START_MIGRATION KVM_ARCH_REQ(3)
> #define KVM_REQ_STOP_MIGRATION KVM_ARCH_REQ(4)
> #define KVM_REQ_VSIE_RESTART KVM_ARCH_REQ(5)
> +#define KVM_REQ_REFRESH_GUEST_PREFIX \
> + KVM_ARCH_REQ_FLAGS(6, KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP)
>
> #define SIGP_CTRL_C 0x80
> #define SIGP_CTRL_SCN_MASK 0x3f
> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
> index dd099d352753..e161df69520c 100644
> --- a/arch/s390/kvm/kvm-s390.c
> +++ b/arch/s390/kvm/kvm-s390.c
> @@ -3394,7 +3394,7 @@ static void kvm_gmap_notifier(struct gmap *gmap, unsigned long start,
> if (prefix <= end && start <= prefix + 2*PAGE_SIZE - 1) {
> VCPU_EVENT(vcpu, 2, "gmap notifier for %lx-%lx",
> start, end);
> - kvm_s390_sync_request(KVM_REQ_MMU_RELOAD, vcpu);
> + kvm_s390_sync_request(KVM_REQ_REFRESH_GUEST_PREFIX, vcpu);
> }
> }
> }
> @@ -3796,19 +3796,19 @@ static int kvm_s390_handle_requests(struct kvm_vcpu *vcpu)
> if (!kvm_request_pending(vcpu))
> return 0;
> /*
> - * We use MMU_RELOAD just to re-arm the ipte notifier for the
> + * If the guest prefix changed, re-arm the ipte notifier for the
> * guest prefix page. gmap_mprotect_notify will wait on the ptl lock.
> * This ensures that the ipte instruction for this request has
> * already finished. We might race against a second unmapper that
> * wants to set the blocking bit. Lets just retry the request loop.
> */
> - if (kvm_check_request(KVM_REQ_MMU_RELOAD, vcpu)) {
> + if (kvm_check_request(KVM_REQ_REFRESH_GUEST_PREFIX, vcpu)) {
> int rc;
> rc = gmap_mprotect_notify(vcpu->arch.gmap,
> kvm_s390_get_prefix(vcpu),
> PAGE_SIZE * 2, PROT_WRITE);
> if (rc) {
> - kvm_make_request(KVM_REQ_MMU_RELOAD, vcpu);
> + kvm_make_request(KVM_REQ_REFRESH_GUEST_PREFIX, vcpu);
> return rc;
> }
> goto retry;
> diff --git a/arch/s390/kvm/kvm-s390.h b/arch/s390/kvm/kvm-s390.h
> index 60f0effcce99..219f92ffd556 100644
> --- a/arch/s390/kvm/kvm-s390.h
> +++ b/arch/s390/kvm/kvm-s390.h
> @@ -105,7 +105,7 @@ static inline void kvm_s390_set_prefix(struct kvm_vcpu *vcpu, u32 prefix)
> prefix);
> vcpu->arch.sie_block->prefix = prefix >> GUEST_PREFIX_SHIFT;
> kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu);
> - kvm_make_request(KVM_REQ_MMU_RELOAD, vcpu);
> + kvm_make_request(KVM_REQ_REFRESH_GUEST_PREFIX, vcpu);
> }
>
> static inline u64 kvm_s390_get_base_disp_s(struct kvm_vcpu *vcpu, u8 *ar)
>
next prev parent reply other threads:[~2021-12-09 10:53 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-09 6:05 [PATCH 0/7] KVM: x86/mmu: Obsolete root shadow page fix Sean Christopherson
2021-12-09 6:05 ` [PATCH 1/7] KVM: x86: Retry page fault if MMU reload is pending and root has no sp Sean Christopherson
2021-12-09 11:19 ` Paolo Bonzini
2021-12-10 12:41 ` Paolo Bonzini
2021-12-10 16:01 ` Sean Christopherson
2021-12-10 16:13 ` Paolo Bonzini
2021-12-10 17:15 ` Sean Christopherson
2021-12-15 18:53 ` Sean Christopherson
2021-12-19 18:41 ` Paolo Bonzini
2021-12-09 6:05 ` [PATCH 2/7] KVM: x86: Invoke kvm_mmu_unload() directly on CR4.PCIDE change Sean Christopherson
2021-12-09 6:05 ` [PATCH 3/7] KVM: Drop kvm_reload_remote_mmus(), open code request in x86 users Sean Christopherson
2021-12-09 6:05 ` [PATCH 4/7] KVM: x86/mmu: Zap only obsolete roots if a root shadow page is zapped Sean Christopherson
2021-12-09 6:05 ` [PATCH 5/7] KVM: s390: Replace KVM_REQ_MMU_RELOAD usage with arch specific request Sean Christopherson
2021-12-09 9:14 ` Claudio Imbrenda
2021-12-09 10:52 ` Janosch Frank [this message]
2021-12-09 6:05 ` [PATCH 6/7] KVM: Drop KVM_REQ_MMU_RELOAD and update vcpu-requests.rst documentation Sean Christopherson
2021-12-09 8:17 ` Claudio Imbrenda
2021-12-09 6:05 ` [PATCH 7/7] KVM: WARN if is_unsync_root() is called on a root without a shadow page Sean Christopherson
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