linux-kernel - [PATCH v4 02/37] KVM: x86: hyper-v: Resurrect dedicated KVM_REQ_HV_TLB

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20220525090133.1264239-3-vkuznets@redhat.com>
Date:   Wed, 25 May 2022 11:00:58 +0200
From:   Vitaly Kuznetsov <vkuznets@...hat.com>
To:     kvm@...r.kernel.org, Paolo Bonzini <pbonzini@...hat.com>
Cc:     Sean Christopherson <seanjc@...gle.com>,
        Maxim Levitsky <mlevitsk@...hat.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>,
        Michael Kelley <mikelley@...rosoft.com>,
        Siddharth Chandrasekaran <sidcha@...zon.de>,
        linux-hyperv@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH v4 02/37] KVM: x86: hyper-v: Resurrect dedicated KVM_REQ_HV_TLB_FLUSH flag

In preparation to implementing fine-grained Hyper-V TLB flush and
L2 TLB flush, resurrect dedicated KVM_REQ_HV_TLB_FLUSH request bit. As
KVM_REQ_TLB_FLUSH_GUEST/KVM_REQ_TLB_FLUSH_GUEST/KVM_REQ_TLB_FLUSH_CURRENT
are stronger operations, clear KVM_REQ_HV_TLB_FLUSH request in
kvm_service_local_tlb_flush_requests() when any of these were also
requested.

No (real) functional change intended.

Signed-off-by: Vitaly Kuznetsov <vkuznets@...hat.com>
---
 arch/x86/include/asm/kvm_host.h |  2 ++
 arch/x86/kvm/hyperv.c           |  4 ++--
 arch/x86/kvm/x86.c              | 10 ++++++++--
 3 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 151880cfab9e..92509ee6ae1b 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -105,6 +105,8 @@
 	KVM_ARCH_REQ_FLAGS(30, KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP)
 #define KVM_REQ_MMU_FREE_OBSOLETE_ROOTS \
 	KVM_ARCH_REQ_FLAGS(31, KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP)
+#define KVM_REQ_HV_TLB_FLUSH \
+	KVM_ARCH_REQ_FLAGS(32, KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP)
 
 #define CR0_RESERVED_BITS                                               \
 	(~(unsigned long)(X86_CR0_PE | X86_CR0_MP | X86_CR0_EM | X86_CR0_TS \
diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
index 46f9dfb60469..b402ad059eb9 100644
--- a/arch/x86/kvm/hyperv.c
+++ b/arch/x86/kvm/hyperv.c
@@ -1876,11 +1876,11 @@ static u64 kvm_hv_flush_tlb(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc)
 	 * analyze it here, flush TLB regardless of the specified address space.
 	 */
 	if (all_cpus) {
-		kvm_make_all_cpus_request(kvm, KVM_REQ_TLB_FLUSH_GUEST);
+		kvm_make_all_cpus_request(kvm, KVM_REQ_HV_TLB_FLUSH);
 	} else {
 		sparse_set_to_vcpu_mask(kvm, sparse_banks, valid_bank_mask, vcpu_mask);
 
-		kvm_make_vcpus_request_mask(kvm, KVM_REQ_TLB_FLUSH_GUEST, vcpu_mask);
+		kvm_make_vcpus_request_mask(kvm, KVM_REQ_HV_TLB_FLUSH, vcpu_mask);
 	}
 
 ret_success:
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 891507b2eca5..f98503431f8d 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3363,11 +3363,17 @@ static inline void kvm_vcpu_flush_tlb_current(struct kvm_vcpu *vcpu)
  */
 void kvm_service_local_tlb_flush_requests(struct kvm_vcpu *vcpu)
 {
-	if (kvm_check_request(KVM_REQ_TLB_FLUSH_CURRENT, vcpu))
+	if (kvm_check_request(KVM_REQ_TLB_FLUSH_CURRENT, vcpu)) {
 		kvm_vcpu_flush_tlb_current(vcpu);
+		kvm_clear_request(KVM_REQ_HV_TLB_FLUSH, vcpu);
+	}
 
-	if (kvm_check_request(KVM_REQ_TLB_FLUSH_GUEST, vcpu))
+	if (kvm_check_request(KVM_REQ_TLB_FLUSH_GUEST, vcpu)) {
+		kvm_vcpu_flush_tlb_guest(vcpu);
+		kvm_clear_request(KVM_REQ_HV_TLB_FLUSH, vcpu);
+	} else if (kvm_check_request(KVM_REQ_HV_TLB_FLUSH, vcpu)) {
 		kvm_vcpu_flush_tlb_guest(vcpu);
+	}
 }
 EXPORT_SYMBOL_GPL(kvm_service_local_tlb_flush_requests);
 
-- 
2.35.3