From c7e3ba64ba16eddfbfc66ec099860f40e808e124 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Wed, 23 Jan 2013 13:21:59 -0500 Subject: ARM: KVM: arch_timers: Add timer world switch Do the necessary save/restore dance for the timers in the world switch code. In the process, allow the guest to read the physical counter, which is useful for its own clock_event_device. Reviewed-by: Will Deacon Signed-off-by: Christoffer Dall Signed-off-by: Marc Zyngier --- arch/arm/include/asm/kvm_asm.h | 3 ++- arch/arm/kernel/asm-offsets.c | 6 +++++ arch/arm/kvm/arm.c | 3 +++ arch/arm/kvm/coproc.c | 4 +++ arch/arm/kvm/interrupts_head.S | 59 ++++++++++++++++++++++++++++++++++++++++++ 5 files changed, 74 insertions(+), 1 deletion(-) diff --git a/arch/arm/include/asm/kvm_asm.h b/arch/arm/include/asm/kvm_asm.h index 5e06e8177784..e4956f4e23e1 100644 --- a/arch/arm/include/asm/kvm_asm.h +++ b/arch/arm/include/asm/kvm_asm.h @@ -45,7 +45,8 @@ #define c13_TID_URW 23 /* Thread ID, User R/W */ #define c13_TID_URO 24 /* Thread ID, User R/O */ #define c13_TID_PRIV 25 /* Thread ID, Privileged */ -#define NR_CP15_REGS 26 /* Number of regs (incl. invalid) */ +#define c14_CNTKCTL 26 /* Timer Control Register (PL1) */ +#define NR_CP15_REGS 27 /* Number of regs (incl. invalid) */ #define ARM_EXCEPTION_RESET 0 #define ARM_EXCEPTION_UNDEFINED 1 diff --git a/arch/arm/kernel/asm-offsets.c b/arch/arm/kernel/asm-offsets.c index 17cea2e78d88..5ce738b43508 100644 --- a/arch/arm/kernel/asm-offsets.c +++ b/arch/arm/kernel/asm-offsets.c @@ -179,6 +179,12 @@ int main(void) DEFINE(VGIC_CPU_APR, offsetof(struct vgic_cpu, vgic_apr)); DEFINE(VGIC_CPU_LR, offsetof(struct vgic_cpu, vgic_lr)); DEFINE(VGIC_CPU_NR_LR, offsetof(struct vgic_cpu, nr_lr)); +#ifdef CONFIG_KVM_ARM_TIMER + DEFINE(VCPU_TIMER_CNTV_CTL, offsetof(struct kvm_vcpu, arch.timer_cpu.cntv_ctl)); + DEFINE(VCPU_TIMER_CNTV_CVAL, offsetof(struct kvm_vcpu, arch.timer_cpu.cntv_cval)); + DEFINE(KVM_TIMER_CNTVOFF, offsetof(struct kvm, arch.timer.cntvoff)); + DEFINE(KVM_TIMER_ENABLED, offsetof(struct kvm, arch.timer.enabled)); +#endif DEFINE(KVM_VGIC_VCTRL, offsetof(struct kvm, arch.vgic.vctrl_base)); #endif DEFINE(KVM_VTTBR, offsetof(struct kvm, arch.vttbr)); diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c index ea7383293ed0..800b2cd804d3 100644 --- a/arch/arm/kvm/arm.c +++ b/arch/arm/kvm/arm.c @@ -718,6 +718,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run) vcpu_pause(vcpu); kvm_vgic_flush_hwstate(vcpu); + kvm_timer_flush_hwstate(vcpu); local_irq_disable(); @@ -731,6 +732,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run) if (ret <= 0 || need_new_vmid_gen(vcpu->kvm)) { local_irq_enable(); + kvm_timer_sync_hwstate(vcpu); kvm_vgic_sync_hwstate(vcpu); continue; } @@ -764,6 +766,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run) * Back from guest *************************************************************/ + kvm_timer_sync_hwstate(vcpu); kvm_vgic_sync_hwstate(vcpu); ret = handle_exit(vcpu, run, ret); diff --git a/arch/arm/kvm/coproc.c b/arch/arm/kvm/coproc.c index d782638c7ec0..4ea9a982269c 100644 --- a/arch/arm/kvm/coproc.c +++ b/arch/arm/kvm/coproc.c @@ -222,6 +222,10 @@ static const struct coproc_reg cp15_regs[] = { NULL, reset_unknown, c13_TID_URO }, { CRn(13), CRm( 0), Op1( 0), Op2( 4), is32, NULL, reset_unknown, c13_TID_PRIV }, + + /* CNTKCTL: swapped by interrupt.S. */ + { CRn(14), CRm( 1), Op1( 0), Op2( 0), is32, + NULL, reset_val, c14_CNTKCTL, 0x00000000 }, }; /* Target specific emulation tables */ diff --git a/arch/arm/kvm/interrupts_head.S b/arch/arm/kvm/interrupts_head.S index 06f251395bec..3c8f2f0b4c5e 100644 --- a/arch/arm/kvm/interrupts_head.S +++ b/arch/arm/kvm/interrupts_head.S @@ -300,6 +300,14 @@ vcpu .req r0 @ vcpu pointer always in r0 str r11, [vcpu, #CP15_OFFSET(c6_IFAR)] str r12, [vcpu, #CP15_OFFSET(c12_VBAR)] .endif + + mrc p15, 0, r2, c14, c1, 0 @ CNTKCTL + + .if \store_to_vcpu == 0 + push {r2} + .else + str r2, [vcpu, #CP15_OFFSET(c14_CNTKCTL)] + .endif .endm /* @@ -310,6 +318,14 @@ vcpu .req r0 @ vcpu pointer always in r0 * Assumes vcpu pointer in vcpu reg */ .macro write_cp15_state read_from_vcpu + .if \read_from_vcpu == 0 + pop {r2} + .else + ldr r2, [vcpu, #CP15_OFFSET(c14_CNTKCTL)] + .endif + + mcr p15, 0, r2, c14, c1, 0 @ CNTKCTL + .if \read_from_vcpu == 0 pop {r2-r12} .else @@ -461,8 +477,28 @@ vcpu .req r0 @ vcpu pointer always in r0 * for the host. * * Assumes vcpu pointer in vcpu reg + * Clobbers r2-r5 */ .macro save_timer_state +#ifdef CONFIG_KVM_ARM_TIMER + ldr r4, [vcpu, #VCPU_KVM] + ldr r2, [r4, #KVM_TIMER_ENABLED] + cmp r2, #0 + beq 1f + + mrc p15, 0, r2, c14, c3, 1 @ CNTV_CTL + str r2, [vcpu, #VCPU_TIMER_CNTV_CTL] + bic r2, #1 @ Clear ENABLE + mcr p15, 0, r2, c14, c3, 1 @ CNTV_CTL + isb + + mrrc p15, 3, r2, r3, c14 @ CNTV_CVAL + ldr r4, =VCPU_TIMER_CNTV_CVAL + add r5, vcpu, r4 + strd r2, r3, [r5] + +1: +#endif @ Allow physical timer/counter access for the host mrc p15, 4, r2, c14, c1, 0 @ CNTHCTL orr r2, r2, #(CNTHCTL_PL1PCEN | CNTHCTL_PL1PCTEN) @@ -474,6 +510,7 @@ vcpu .req r0 @ vcpu pointer always in r0 * for the host. * * Assumes vcpu pointer in vcpu reg + * Clobbers r2-r5 */ .macro restore_timer_state @ Disallow physical timer access for the guest @@ -482,6 +519,28 @@ vcpu .req r0 @ vcpu pointer always in r0 orr r2, r2, #CNTHCTL_PL1PCTEN bic r2, r2, #CNTHCTL_PL1PCEN mcr p15, 4, r2, c14, c1, 0 @ CNTHCTL + +#ifdef CONFIG_KVM_ARM_TIMER + ldr r4, [vcpu, #VCPU_KVM] + ldr r2, [r4, #KVM_TIMER_ENABLED] + cmp r2, #0 + beq 1f + + ldr r2, [r4, #KVM_TIMER_CNTVOFF] + ldr r3, [r4, #(KVM_TIMER_CNTVOFF + 4)] + mcrr p15, 4, r2, r3, c14 @ CNTVOFF + + ldr r4, =VCPU_TIMER_CNTV_CVAL + add r5, vcpu, r4 + ldrd r2, r3, [r5] + mcrr p15, 3, r2, r3, c14 @ CNTV_CVAL + isb + + ldr r2, [vcpu, #VCPU_TIMER_CNTV_CTL] + and r2, r2, #3 + mcr p15, 0, r2, c14, c3, 1 @ CNTV_CTL +1: +#endif .endm .equ vmentry, 0 -- cgit v1.2.3