From 199b5763d329b43c88f6ad539db8a6c6b42f8edb Mon Sep 17 00:00:00 2001 From: "Longpeng(Mike)" Date: Tue, 8 Aug 2017 12:05:32 +0800 Subject: KVM: add spinlock optimization framework If a vcpu exits due to request a user mode spinlock, then the spinlock-holder may be preempted in user mode or kernel mode. (Note that not all architectures trap spin loops in user mode, only AMD x86 and ARM/ARM64 currently do). But if a vcpu exits in kernel mode, then the holder must be preempted in kernel mode, so we should choose a vcpu in kernel mode as a more likely candidate for the lock holder. This introduces kvm_arch_vcpu_in_kernel() to decide whether the vcpu is in kernel-mode when it's preempted. kvm_vcpu_on_spin's new argument says the same of the spinning VCPU. Signed-off-by: Longpeng(Mike) Signed-off-by: Paolo Bonzini --- arch/arm64/kvm/handle_exit.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/arm64/kvm') diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c index 17d8a1677a0b..da57622cacca 100644 --- a/arch/arm64/kvm/handle_exit.c +++ b/arch/arm64/kvm/handle_exit.c @@ -84,7 +84,7 @@ static int kvm_handle_wfx(struct kvm_vcpu *vcpu, struct kvm_run *run) if (kvm_vcpu_get_hsr(vcpu) & ESR_ELx_WFx_ISS_WFE) { trace_kvm_wfx_arm64(*vcpu_pc(vcpu), true); vcpu->stat.wfe_exit_stat++; - kvm_vcpu_on_spin(vcpu); + kvm_vcpu_on_spin(vcpu, false); } else { trace_kvm_wfx_arm64(*vcpu_pc(vcpu), false); vcpu->stat.wfi_exit_stat++; -- cgit v1.2.3-59-g8ed1b From f01fbd2fad73434f62cbd0aada8f9403fc0fa527 Mon Sep 17 00:00:00 2001 From: "Longpeng(Mike)" Date: Tue, 8 Aug 2017 12:05:35 +0800 Subject: KVM: arm: implements the kvm_arch_vcpu_in_kernel() This implements the kvm_arch_vcpu_in_kernel() for ARM, and adjusts the calls to kvm_vcpu_on_spin(). Signed-off-by: Longpeng(Mike) Signed-off-by: Paolo Bonzini --- arch/arm/kvm/handle_exit.c | 2 +- arch/arm64/kvm/handle_exit.c | 2 +- virt/kvm/arm/arm.c | 2 +- 3 files changed, 3 insertions(+), 3 deletions(-) (limited to 'arch/arm64/kvm') diff --git a/arch/arm/kvm/handle_exit.c b/arch/arm/kvm/handle_exit.c index 196122bb6968..cf8bf6bf87c4 100644 --- a/arch/arm/kvm/handle_exit.c +++ b/arch/arm/kvm/handle_exit.c @@ -67,7 +67,7 @@ static int kvm_handle_wfx(struct kvm_vcpu *vcpu, struct kvm_run *run) if (kvm_vcpu_get_hsr(vcpu) & HSR_WFI_IS_WFE) { trace_kvm_wfx(*vcpu_pc(vcpu), true); vcpu->stat.wfe_exit_stat++; - kvm_vcpu_on_spin(vcpu, false); + kvm_vcpu_on_spin(vcpu, vcpu_mode_priv(vcpu)); } else { trace_kvm_wfx(*vcpu_pc(vcpu), false); vcpu->stat.wfi_exit_stat++; diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c index da57622cacca..7debb74843a0 100644 --- a/arch/arm64/kvm/handle_exit.c +++ b/arch/arm64/kvm/handle_exit.c @@ -84,7 +84,7 @@ static int kvm_handle_wfx(struct kvm_vcpu *vcpu, struct kvm_run *run) if (kvm_vcpu_get_hsr(vcpu) & ESR_ELx_WFx_ISS_WFE) { trace_kvm_wfx_arm64(*vcpu_pc(vcpu), true); vcpu->stat.wfe_exit_stat++; - kvm_vcpu_on_spin(vcpu, false); + kvm_vcpu_on_spin(vcpu, vcpu_mode_priv(vcpu)); } else { trace_kvm_wfx_arm64(*vcpu_pc(vcpu), false); vcpu->stat.wfi_exit_stat++; diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c index 862f820d06d4..b9f68e4add71 100644 --- a/virt/kvm/arm/arm.c +++ b/virt/kvm/arm/arm.c @@ -418,7 +418,7 @@ int kvm_arch_vcpu_runnable(struct kvm_vcpu *v) bool kvm_arch_vcpu_in_kernel(struct kvm_vcpu *vcpu) { - return false; + return vcpu_mode_priv(vcpu); } /* Just ensure a guest exit from a particular CPU */ -- cgit v1.2.3-59-g8ed1b From 50f5bd5718df9e71d1f4ba69a6480dbad54b2f24 Mon Sep 17 00:00:00 2001 From: Christoffer Dall Date: Fri, 1 Sep 2017 11:41:52 +0200 Subject: KVM: arm/arm64: Extract GICv3 max APRn index calculation As we are about to access the APRs from the GICv2 uaccess interface, make this logic generally available. Reviewed-by: Marc Zyngier Signed-off-by: Christoffer Dall --- arch/arm64/kvm/vgic-sys-reg-v3.c | 23 +++-------------------- virt/kvm/arm/vgic/vgic.h | 16 ++++++++++++++++ 2 files changed, 19 insertions(+), 20 deletions(-) (limited to 'arch/arm64/kvm') diff --git a/arch/arm64/kvm/vgic-sys-reg-v3.c b/arch/arm64/kvm/vgic-sys-reg-v3.c index 116786d2e8e8..c77d508b7462 100644 --- a/arch/arm64/kvm/vgic-sys-reg-v3.c +++ b/arch/arm64/kvm/vgic-sys-reg-v3.c @@ -208,29 +208,12 @@ static void vgic_v3_access_apr_reg(struct kvm_vcpu *vcpu, static bool access_gic_aprn(struct kvm_vcpu *vcpu, struct sys_reg_params *p, const struct sys_reg_desc *r, u8 apr) { - struct vgic_cpu *vgic_v3_cpu = &vcpu->arch.vgic_cpu; u8 idx = r->Op2 & 3; - /* - * num_pri_bits are initialized with HW supported values. - * We can rely safely on num_pri_bits even if VM has not - * restored ICC_CTLR_EL1 before restoring APnR registers. - */ - switch (vgic_v3_cpu->num_pri_bits) { - case 7: - vgic_v3_access_apr_reg(vcpu, p, apr, idx); - break; - case 6: - if (idx > 1) - goto err; - vgic_v3_access_apr_reg(vcpu, p, apr, idx); - break; - default: - if (idx > 0) - goto err; - vgic_v3_access_apr_reg(vcpu, p, apr, idx); - } + if (idx > vgic_v3_max_apr_idx(vcpu)) + goto err; + vgic_v3_access_apr_reg(vcpu, p, apr, idx); return true; err: if (!p->is_write) diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h index bba7fa22a7f7..bf9ceab67c77 100644 --- a/virt/kvm/arm/vgic/vgic.h +++ b/virt/kvm/arm/vgic/vgic.h @@ -220,4 +220,20 @@ int vgic_debug_destroy(struct kvm *kvm); bool lock_all_vcpus(struct kvm *kvm); void unlock_all_vcpus(struct kvm *kvm); +static inline int vgic_v3_max_apr_idx(struct kvm_vcpu *vcpu) +{ + struct vgic_cpu *cpu_if = &vcpu->arch.vgic_cpu; + + /* + * num_pri_bits are initialized with HW supported values. + * We can rely safely on num_pri_bits even if VM has not + * restored ICC_CTLR_EL1 before restoring APnR registers. + */ + switch (cpu_if->num_pri_bits) { + case 7: return 3; + case 6: return 1; + default: return 0; + } +} + #endif -- cgit v1.2.3-59-g8ed1b