From a92e2543d6a8653a8ab45cf5df7ef07dafcf3f3e Mon Sep 17 00:00:00 2001 From: =?utf8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= Date: Tue, 12 Jul 2016 22:09:22 +0200 Subject: [PATCH] KVM: x86: use hardware-compatible format for APIC ID register MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit We currently always shift APIC ID as if APIC was in xAPIC mode. x2APIC mode wants to use more bits and storing a hardware-compabible value is the the sanest option. KVM API to set the lapic expects that bottom 8 bits of APIC ID are in top 8 bits of APIC_ID register, so the register needs to be shifted in x2APIC mode. Signed-off-by: Radim Krčmář Signed-off-by: Paolo Bonzini --- arch/x86/kvm/lapic.c | 52 +++++++++++++++++++++++++++++++------------- arch/x86/kvm/lapic.h | 12 +++++++--- arch/x86/kvm/x86.c | 10 +++++---- 3 files changed, 52 insertions(+), 22 deletions(-) diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index 224fc1c5fcc6..41089dbeeafc 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -227,7 +227,7 @@ static inline void apic_set_spiv(struct kvm_lapic *apic, u32 val) } } -static inline void kvm_apic_set_id(struct kvm_lapic *apic, u8 id) +static inline void kvm_apic_set_xapic_id(struct kvm_lapic *apic, u8 id) { kvm_lapic_set_reg(apic, APIC_ID, id << 24); recalculate_apic_map(apic->vcpu->kvm); @@ -239,11 +239,11 @@ static inline void kvm_apic_set_ldr(struct kvm_lapic *apic, u32 id) recalculate_apic_map(apic->vcpu->kvm); } -static inline void kvm_apic_set_x2apic_id(struct kvm_lapic *apic, u8 id) +static inline void kvm_apic_set_x2apic_id(struct kvm_lapic *apic, u32 id) { u32 ldr = ((id >> 4) << 16) | (1 << (id & 0xf)); - kvm_lapic_set_reg(apic, APIC_ID, id << 24); + kvm_lapic_set_reg(apic, APIC_ID, id); kvm_lapic_set_reg(apic, APIC_LDR, ldr); recalculate_apic_map(apic->vcpu->kvm); } @@ -1102,12 +1102,6 @@ static u32 __apic_read(struct kvm_lapic *apic, unsigned int offset) return 0; switch (offset) { - case APIC_ID: - if (apic_x2apic_mode(apic)) - val = kvm_apic_id(apic); - else - val = kvm_apic_id(apic) << 24; - break; case APIC_ARBPRI: apic_debug("Access APIC ARBPRI register which is for P6\n"); break; @@ -1465,7 +1459,7 @@ int kvm_lapic_reg_write(struct kvm_lapic *apic, u32 reg, u32 val) switch (reg) { case APIC_ID: /* Local APIC ID */ if (!apic_x2apic_mode(apic)) - kvm_apic_set_id(apic, val >> 24); + kvm_apic_set_xapic_id(apic, val >> 24); else ret = 1; break; @@ -1769,7 +1763,7 @@ void kvm_lapic_reset(struct kvm_vcpu *vcpu, bool init_event) hrtimer_cancel(&apic->lapic_timer.timer); if (!init_event) - kvm_apic_set_id(apic, vcpu->vcpu_id); + kvm_apic_set_xapic_id(apic, vcpu->vcpu_id); kvm_apic_set_version(apic->vcpu); for (i = 0; i < KVM_APIC_LVT_NUM; i++) @@ -1990,17 +1984,43 @@ int kvm_get_apic_interrupt(struct kvm_vcpu *vcpu) return vector; } -void kvm_apic_post_state_restore(struct kvm_vcpu *vcpu, - struct kvm_lapic_state *s) +static int kvm_apic_state_fixup(struct kvm_vcpu *vcpu, + struct kvm_lapic_state *s, bool set) +{ + if (apic_x2apic_mode(vcpu->arch.apic)) { + u32 *id = (u32 *)(s->regs + APIC_ID); + + if (set) + *id >>= 24; + else + *id <<= 24; + } + + return 0; +} + +int kvm_apic_get_state(struct kvm_vcpu *vcpu, struct kvm_lapic_state *s) +{ + memcpy(s->regs, vcpu->arch.apic->regs, sizeof(*s)); + return kvm_apic_state_fixup(vcpu, s, false); +} + +int kvm_apic_set_state(struct kvm_vcpu *vcpu, struct kvm_lapic_state *s) { struct kvm_lapic *apic = vcpu->arch.apic; + int r; + kvm_lapic_set_base(vcpu, vcpu->arch.apic_base); /* set SPIV separately to get count of SW disabled APICs right */ apic_set_spiv(apic, *((u32 *)(s->regs + APIC_SPIV))); + + r = kvm_apic_state_fixup(vcpu, s, true); + if (r) + return r; memcpy(vcpu->arch.apic->regs, s->regs, sizeof *s); - /* call kvm_apic_set_id() to put apic into apic_map */ - kvm_apic_set_id(apic, kvm_apic_id(apic)); + + recalculate_apic_map(vcpu->kvm); kvm_apic_set_version(vcpu); apic_update_ppr(apic); @@ -2026,6 +2046,8 @@ void kvm_apic_post_state_restore(struct kvm_vcpu *vcpu, kvm_rtc_eoi_tracking_restore_one(vcpu); vcpu->arch.apic_arb_prio = 0; + + return 0; } void __kvm_migrate_apic_timer(struct kvm_vcpu *vcpu) diff --git a/arch/x86/kvm/lapic.h b/arch/x86/kvm/lapic.h index 8d811139d2b3..f60d01c29d51 100644 --- a/arch/x86/kvm/lapic.h +++ b/arch/x86/kvm/lapic.h @@ -81,8 +81,8 @@ bool kvm_irq_delivery_to_apic_fast(struct kvm *kvm, struct kvm_lapic *src, u64 kvm_get_apic_base(struct kvm_vcpu *vcpu); int kvm_set_apic_base(struct kvm_vcpu *vcpu, struct msr_data *msr_info); -void kvm_apic_post_state_restore(struct kvm_vcpu *vcpu, - struct kvm_lapic_state *s); +int kvm_apic_get_state(struct kvm_vcpu *vcpu, struct kvm_lapic_state *s); +int kvm_apic_set_state(struct kvm_vcpu *vcpu, struct kvm_lapic_state *s); int kvm_lapic_find_highest_irr(struct kvm_vcpu *vcpu); u64 kvm_get_lapic_tscdeadline_msr(struct kvm_vcpu *vcpu); @@ -202,7 +202,13 @@ static inline int kvm_lapic_latched_init(struct kvm_vcpu *vcpu) static inline u32 kvm_apic_id(struct kvm_lapic *apic) { - return (kvm_lapic_get_reg(apic, APIC_ID) >> 24) & 0xff; + /* To avoid a race between apic_base and following APIC_ID update when + * switching to x2apic_mode, the x2apic mode returns initial x2apic id. + */ + if (apic_x2apic_mode(apic)) + return apic->vcpu->vcpu_id; + + return kvm_lapic_get_reg(apic, APIC_ID) >> 24; } bool kvm_apic_pending_eoi(struct kvm_vcpu *vcpu, int vector); diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 0c1fbb8d9d11..b6e402d16e0c 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -2779,15 +2779,17 @@ static int kvm_vcpu_ioctl_get_lapic(struct kvm_vcpu *vcpu, if (vcpu->arch.apicv_active) kvm_x86_ops->sync_pir_to_irr(vcpu); - memcpy(s->regs, vcpu->arch.apic->regs, sizeof *s); - - return 0; + return kvm_apic_get_state(vcpu, s); } static int kvm_vcpu_ioctl_set_lapic(struct kvm_vcpu *vcpu, struct kvm_lapic_state *s) { - kvm_apic_post_state_restore(vcpu, s); + int r; + + r = kvm_apic_set_state(vcpu, s); + if (r) + return r; update_cr8_intercept(vcpu); return 0; -- 2.20.1