diff options
| author | Marc Zyngier <maz@kernel.org> | 2023-03-30 18:47:53 +0100 |
|---|---|---|
| committer | Marc Zyngier <maz@kernel.org> | 2023-03-30 19:01:10 +0100 |
| commit | e9adde432bf7371f1c83f67d9f8d75b95810f124 (patch) | |
| tree | 86910413cc1d9e42590e1d7b14c5f84bd22d092c /arch/arm64/kvm/hyp/include/hyp/switch.h | |
| parent | 1a6511eb8430533920559c5f01f487f4901081cd (diff) | |
KVM: arm64: timers: Fast-track CNTPCT_EL0 trap handling
Now that it is likely that CNTPCT_EL0 accesses will trap,
fast-track the emulation of the counter read which doesn't
need more that a simple offsetting.
One day, we'll have CNTPOFF everywhere. One day.
Suggested-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230330174800.2677007-14-maz@kernel.org
Diffstat (limited to 'arch/arm64/kvm/hyp/include/hyp/switch.h')
| -rw-r--r-- | arch/arm64/kvm/hyp/include/hyp/switch.h | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/arch/arm64/kvm/hyp/include/hyp/switch.h b/arch/arm64/kvm/hyp/include/hyp/switch.h index 07d37ff88a3f..9954368f639d 100644 --- a/arch/arm64/kvm/hyp/include/hyp/switch.h +++ b/arch/arm64/kvm/hyp/include/hyp/switch.h @@ -26,6 +26,7 @@ #include <asm/kvm_emulate.h> #include <asm/kvm_hyp.h> #include <asm/kvm_mmu.h> +#include <asm/kvm_nested.h> #include <asm/fpsimd.h> #include <asm/debug-monitors.h> #include <asm/processor.h> @@ -326,6 +327,38 @@ static bool kvm_hyp_handle_ptrauth(struct kvm_vcpu *vcpu, u64 *exit_code) return true; } +static bool kvm_hyp_handle_cntpct(struct kvm_vcpu *vcpu) +{ + struct arch_timer_context *ctxt; + u32 sysreg; + u64 val; + + /* + * We only get here for 64bit guests, 32bit guests will hit + * the long and winding road all the way to the standard + * handling. Yes, it sucks to be irrelevant. + */ + sysreg = esr_sys64_to_sysreg(kvm_vcpu_get_esr(vcpu)); + + switch (sysreg) { + case SYS_CNTPCT_EL0: + case SYS_CNTPCTSS_EL0: + ctxt = vcpu_ptimer(vcpu); + break; + default: + return false; + } + + val = arch_timer_read_cntpct_el0(); + + if (ctxt->offset.vm_offset) + val -= *kern_hyp_va(ctxt->offset.vm_offset); + + vcpu_set_reg(vcpu, kvm_vcpu_sys_get_rt(vcpu), val); + __kvm_skip_instr(vcpu); + return true; +} + static bool kvm_hyp_handle_sysreg(struct kvm_vcpu *vcpu, u64 *exit_code) { if (cpus_have_final_cap(ARM64_WORKAROUND_CAVIUM_TX2_219_TVM) && @@ -339,6 +372,9 @@ static bool kvm_hyp_handle_sysreg(struct kvm_vcpu *vcpu, u64 *exit_code) if (esr_is_ptrauth_trap(kvm_vcpu_get_esr(vcpu))) return kvm_hyp_handle_ptrauth(vcpu, exit_code); + if (kvm_hyp_handle_cntpct(vcpu)) + return true; + return false; } |