We need to allow a guest hypervisor to virtualize the virtual timer. FOr that, let's propagate CNTVOFF_EL2 to the guest's view of that timer.
Signed-off-by: Marc Zyngier <[email protected]> --- arch/arm64/include/asm/kvm_host.h | 1 - arch/arm64/kvm/sys_regs.c | 8 ++++++-- include/kvm/arm_arch_timer.h | 1 + virt/kvm/arm/arch_timer.c | 12 ++++++++++++ 4 files changed, 19 insertions(+), 3 deletions(-) diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index b7c44adcdbf3..e0fe9acb46bf 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -252,7 +252,6 @@ enum vcpu_sysreg { RMR_EL2, /* Reset Management Register */ CONTEXTIDR_EL2, /* Context ID Register (EL2) */ TPIDR_EL2, /* EL2 Software Thread ID Register */ - CNTVOFF_EL2, /* Counter-timer Virtual Offset register */ CNTHCTL_EL2, /* Counter-timer Hypervisor Control register */ SP_EL2, /* EL2 Stack Pointer */ diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 1b8016330a19..2031a59fcf49 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -150,7 +150,6 @@ struct el2_sysreg_map { PURE_EL2_SYSREG( RVBAR_EL2 ), PURE_EL2_SYSREG( RMR_EL2 ), PURE_EL2_SYSREG( TPIDR_EL2 ), - PURE_EL2_SYSREG( CNTVOFF_EL2 ), PURE_EL2_SYSREG( CNTHCTL_EL2 ), PURE_EL2_SYSREG( HPFAR_EL2 ), EL2_SYSREG( SCTLR_EL2, SCTLR_EL1, translate_sctlr ), @@ -1351,6 +1350,11 @@ static bool access_arch_timer(struct kvm_vcpu *vcpu, tmr = TIMER_PTIMER; treg = TIMER_REG_CVAL; break; + case SYS_CNTVOFF_EL2: + tmr = TIMER_VTIMER; + treg = TIMER_REG_VOFF; + break; + default: BUG(); } @@ -2122,7 +2126,7 @@ static const struct sys_reg_desc sys_reg_descs[] = { { SYS_DESC(SYS_CONTEXTIDR_EL2), access_rw, reset_val, CONTEXTIDR_EL2, 0 }, { SYS_DESC(SYS_TPIDR_EL2), access_rw, reset_val, TPIDR_EL2, 0 }, - { SYS_DESC(SYS_CNTVOFF_EL2), access_rw, reset_val, CNTVOFF_EL2, 0 }, + { SYS_DESC(SYS_CNTVOFF_EL2), access_arch_timer }, { SYS_DESC(SYS_CNTHCTL_EL2), access_rw, reset_val, CNTHCTL_EL2, 0 }, { SYS_DESC(SYS_CNTHP_TVAL_EL2), access_arch_timer }, diff --git a/include/kvm/arm_arch_timer.h b/include/kvm/arm_arch_timer.h index 3a5d9255120e..3389606f3029 100644 --- a/include/kvm/arm_arch_timer.h +++ b/include/kvm/arm_arch_timer.h @@ -23,6 +23,7 @@ enum kvm_arch_timer_regs { TIMER_REG_CVAL, TIMER_REG_TVAL, TIMER_REG_CTL, + TIMER_REG_VOFF, }; struct arch_timer_context { diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c index 3d84c240071d..1d53352c7d97 100644 --- a/virt/kvm/arm/arch_timer.c +++ b/virt/kvm/arm/arch_timer.c @@ -913,6 +913,10 @@ static u64 kvm_arm_timer_read(struct kvm_vcpu *vcpu, val = kvm_phys_timer_read() - timer->cntvoff; break; + case TIMER_REG_VOFF: + val = timer->cntvoff; + break; + default: BUG(); } @@ -955,6 +959,10 @@ static void kvm_arm_timer_write(struct kvm_vcpu *vcpu, timer->cnt_cval = val; break; + case TIMER_REG_VOFF: + timer->cntvoff = val; + break; + default: BUG(); } @@ -1166,6 +1174,10 @@ int kvm_timer_enable(struct kvm_vcpu *vcpu) return -EINVAL; } + /* Nested virtualization requires zero offset for virtual EL2 */ + if (nested_virt_in_use(vcpu)) + vcpu_vtimer(vcpu)->cntvoff = 0; + get_timer_map(vcpu, &map); ret = kvm_vgic_map_phys_irq(vcpu, -- 2.20.1 _______________________________________________ kvmarm mailing list [email protected] https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
