From 2387149eade25f32dcf1398811b3d0293181d005 Mon Sep 17 00:00:00 2001 From: Andrew Jones Date: Sun, 4 Jun 2017 14:43:51 +0200 Subject: KVM: improve arch vcpu request defining Marc Zyngier suggested that we define the arch specific VCPU request base, rather than requiring each arch to remember to start from 8. That suggestion, along with Radim Krcmar's recent VCPU request flag addition, snowballed into defining something of an arch VCPU request defining API. No functional change. (Looks like x86 is running out of arch VCPU request bits. Maybe someday we'll need to extend to 64.) Signed-off-by: Andrew Jones Acked-by: Christoffer Dall Signed-off-by: Christoffer Dall --- arch/s390/include/asm/kvm_host.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'arch/s390') diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h index 426614a882a9..9c3bd94204ac 100644 --- a/arch/s390/include/asm/kvm_host.h +++ b/arch/s390/include/asm/kvm_host.h @@ -42,9 +42,9 @@ #define KVM_HALT_POLL_NS_DEFAULT 80000 /* s390-specific vcpu->requests bit members */ -#define KVM_REQ_ENABLE_IBS 8 -#define KVM_REQ_DISABLE_IBS 9 -#define KVM_REQ_ICPT_OPEREXC 10 +#define KVM_REQ_ENABLE_IBS KVM_ARCH_REQ(0) +#define KVM_REQ_DISABLE_IBS KVM_ARCH_REQ(1) +#define KVM_REQ_ICPT_OPEREXC KVM_ARCH_REQ(2) #define SIGP_CTRL_C 0x80 #define SIGP_CTRL_SCN_MASK 0x3f -- cgit v1.2.3 From 2fa6e1e12a024b48b2c7ea39f50205246e027da7 Mon Sep 17 00:00:00 2001 From: Radim Krčmář Date: Sun, 4 Jun 2017 14:43:52 +0200 Subject: KVM: add kvm_request_pending MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit A first step in vcpu->requests encapsulation. Additionally, we now use READ_ONCE() when accessing vcpu->requests, which ensures we always load vcpu->requests when it's accessed. This is important as other threads can change it any time. Also, READ_ONCE() documents that vcpu->requests is used with other threads, likely requiring memory barriers, which it does. Signed-off-by: Radim Krčmář [ Documented the new use of READ_ONCE() and converted another check in arch/mips/kvm/vz.c ] Signed-off-by: Andrew Jones Acked-by: Christoffer Dall Signed-off-by: Christoffer Dall --- arch/mips/kvm/trap_emul.c | 2 +- arch/mips/kvm/vz.c | 2 +- arch/powerpc/kvm/booke.c | 2 +- arch/powerpc/kvm/powerpc.c | 5 ++--- arch/s390/kvm/kvm-s390.c | 2 +- arch/x86/kvm/x86.c | 4 ++-- include/linux/kvm_host.h | 5 +++++ 7 files changed, 13 insertions(+), 9 deletions(-) (limited to 'arch/s390') diff --git a/arch/mips/kvm/trap_emul.c b/arch/mips/kvm/trap_emul.c index a563759fd142..6a0d7040d882 100644 --- a/arch/mips/kvm/trap_emul.c +++ b/arch/mips/kvm/trap_emul.c @@ -1094,7 +1094,7 @@ static void kvm_trap_emul_check_requests(struct kvm_vcpu *vcpu, int cpu, struct mm_struct *mm; int i; - if (likely(!vcpu->requests)) + if (likely(!kvm_request_pending(vcpu))) return; if (kvm_check_request(KVM_REQ_TLB_FLUSH, vcpu)) { diff --git a/arch/mips/kvm/vz.c b/arch/mips/kvm/vz.c index 71d8856ade64..74805035edc8 100644 --- a/arch/mips/kvm/vz.c +++ b/arch/mips/kvm/vz.c @@ -2337,7 +2337,7 @@ static int kvm_vz_check_requests(struct kvm_vcpu *vcpu, int cpu) int ret = 0; int i; - if (!vcpu->requests) + if (!kvm_request_pending(vcpu)) return 0; if (kvm_check_request(KVM_REQ_TLB_FLUSH, vcpu)) { diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c index 3eaac3809977..071b87ee682f 100644 --- a/arch/powerpc/kvm/booke.c +++ b/arch/powerpc/kvm/booke.c @@ -687,7 +687,7 @@ int kvmppc_core_prepare_to_enter(struct kvm_vcpu *vcpu) kvmppc_core_check_exceptions(vcpu); - if (vcpu->requests) { + if (kvm_request_pending(vcpu)) { /* Exception delivery raised request; start over */ return 1; } diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c index f7cf2cd564ef..fd64f087737c 100644 --- a/arch/powerpc/kvm/powerpc.c +++ b/arch/powerpc/kvm/powerpc.c @@ -55,8 +55,7 @@ EXPORT_SYMBOL_GPL(kvmppc_pr_ops); int kvm_arch_vcpu_runnable(struct kvm_vcpu *v) { - return !!(v->arch.pending_exceptions) || - v->requests; + return !!(v->arch.pending_exceptions) || kvm_request_pending(v); } int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu) @@ -108,7 +107,7 @@ int kvmppc_prepare_to_enter(struct kvm_vcpu *vcpu) */ smp_mb(); - if (vcpu->requests) { + if (kvm_request_pending(vcpu)) { /* Make sure we process requests preemptable */ local_irq_enable(); trace_kvm_check_requests(vcpu); diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 689ac48361c6..ad41e0fa3a21 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -2440,7 +2440,7 @@ static int kvm_s390_handle_requests(struct kvm_vcpu *vcpu) { retry: kvm_s390_vcpu_request_handled(vcpu); - if (!vcpu->requests) + if (!kvm_request_pending(vcpu)) return 0; /* * We use MMU_RELOAD just to re-arm the ipte notifier for the diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 464da936c53d..f81060518635 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -6710,7 +6710,7 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) bool req_immediate_exit = false; - if (vcpu->requests) { + if (kvm_request_pending(vcpu)) { if (kvm_check_request(KVM_REQ_MMU_RELOAD, vcpu)) kvm_mmu_unload(vcpu); if (kvm_check_request(KVM_REQ_MIGRATE_TIMER, vcpu)) @@ -6874,7 +6874,7 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) kvm_x86_ops->sync_pir_to_irr(vcpu); } - if (vcpu->mode == EXITING_GUEST_MODE || vcpu->requests + if (vcpu->mode == EXITING_GUEST_MODE || kvm_request_pending(vcpu) || need_resched() || signal_pending(current)) { vcpu->mode = OUTSIDE_GUEST_MODE; smp_wmb(); diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 3724b51aab64..0b50e7b35ed4 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -1105,6 +1105,11 @@ static inline void kvm_make_request(int req, struct kvm_vcpu *vcpu) set_bit(req & KVM_REQUEST_MASK, &vcpu->requests); } +static inline bool kvm_request_pending(struct kvm_vcpu *vcpu) +{ + return READ_ONCE(vcpu->requests); +} + static inline bool kvm_test_request(int req, struct kvm_vcpu *vcpu) { return test_bit(req & KVM_REQUEST_MASK, &vcpu->requests); -- cgit v1.2.3