summaryrefslogtreecommitdiffstats
path: root/arch/arm64/kvm/debug.c
diff options
context:
space:
mode:
authorSuzuki K Poulose <suzuki.poulose@arm.com>2021-04-05 18:42:54 +0200
committerMathieu Poirier <mathieu.poirier@linaro.org>2021-04-07 00:05:28 +0200
commita1319260bf62951e279ea228f682bf4b8834a3c2 (patch)
tree856ce34e19e6189e4e931e6f58ec2df84dec1f13 /arch/arm64/kvm/debug.c
parentKVM: arm64: Move SPE availability check to VCPU load (diff)
downloadlinux-a1319260bf62951e279ea228f682bf4b8834a3c2.tar.xz
linux-a1319260bf62951e279ea228f682bf4b8834a3c2.zip
arm64: KVM: Enable access to TRBE support for host
For a nvhe host, the EL2 must allow the EL1&0 translation regime for TraceBuffer (MDCR_EL2.E2TB == 0b11). This must be saved/restored over a trip to the guest. Also, before entering the guest, we must flush any trace data if the TRBE was enabled. And we must prohibit the generation of trace while we are in EL1 by clearing the TRFCR_EL1. For vhe, the EL2 must prevent the EL1 access to the Trace Buffer. The MDCR_EL2 bit definitions for TRBE are available here : https://developer.arm.com/documentation/ddi0601/2020-12/AArch64-Registers/ Cc: Will Deacon <will@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Acked-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210405164307.1720226-8-suzuki.poulose@arm.com Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Diffstat (limited to 'arch/arm64/kvm/debug.c')
-rw-r--r--arch/arm64/kvm/debug.c14
1 files changed, 10 insertions, 4 deletions
diff --git a/arch/arm64/kvm/debug.c b/arch/arm64/kvm/debug.c
index b6d2c33ad1df..6f992c696911 100644
--- a/arch/arm64/kvm/debug.c
+++ b/arch/arm64/kvm/debug.c
@@ -89,7 +89,7 @@ void kvm_arm_reset_debug_ptr(struct kvm_vcpu *vcpu)
* - Debug ROM Address (MDCR_EL2_TDRA)
* - OS related registers (MDCR_EL2_TDOSA)
* - Statistical profiler (MDCR_EL2_TPMS/MDCR_EL2_E2PB)
- * - Self-hosted Trace Filter controls (MDCR_EL2_TTRF)
+ * - Self-hosted Trace (MDCR_EL2_TTRF/MDCR_EL2_E2TB)
*
* Additionally, KVM only traps guest accesses to the debug registers if
* the guest is not actively using them (see the KVM_ARM64_DEBUG_DIRTY
@@ -107,8 +107,8 @@ void kvm_arm_setup_debug(struct kvm_vcpu *vcpu)
trace_kvm_arm_setup_debug(vcpu, vcpu->guest_debug);
/*
- * This also clears MDCR_EL2_E2PB_MASK to disable guest access
- * to the profiling buffer.
+ * This also clears MDCR_EL2_E2PB_MASK and MDCR_EL2_E2TB_MASK
+ * to disable guest access to the profiling and trace buffers
*/
vcpu->arch.mdcr_el2 = __this_cpu_read(mdcr_el2) & MDCR_EL2_HPMN_MASK;
vcpu->arch.mdcr_el2 |= (MDCR_EL2_TPM |
@@ -248,9 +248,15 @@ void kvm_arch_vcpu_load_debug_state_flags(struct kvm_vcpu *vcpu)
if (cpuid_feature_extract_unsigned_field(dfr0, ID_AA64DFR0_PMSVER_SHIFT) &&
!(read_sysreg_s(SYS_PMBIDR_EL1) & BIT(SYS_PMBIDR_EL1_P_SHIFT)))
vcpu->arch.flags |= KVM_ARM64_DEBUG_STATE_SAVE_SPE;
+
+ /* Check if we have TRBE implemented and available at the host */
+ if (cpuid_feature_extract_unsigned_field(dfr0, ID_AA64DFR0_TRBE_SHIFT) &&
+ !(read_sysreg_s(SYS_TRBIDR_EL1) & TRBIDR_PROG))
+ vcpu->arch.flags |= KVM_ARM64_DEBUG_STATE_SAVE_TRBE;
}
void kvm_arch_vcpu_put_debug_state_flags(struct kvm_vcpu *vcpu)
{
- vcpu->arch.flags &= ~KVM_ARM64_DEBUG_STATE_SAVE_SPE;
+ vcpu->arch.flags &= ~(KVM_ARM64_DEBUG_STATE_SAVE_SPE |
+ KVM_ARM64_DEBUG_STATE_SAVE_TRBE);
}