[PATCH v3 3/6] arm64: KVM: Add iflag for FEAT_TRF
flat view
STALE1056d
SUPERSEDED
From: James Clark <hidden>
Date: 2023-10-19 16:56:25
Also in:
kvmarm, lkml
Subsystem:
arm64 port (aarch64 architecture), kernel virtual machine for arm64 (kvm/arm64), the rest · Maintainers:
Catalin Marinas, Will Deacon, Marc Zyngier, Oliver Upton, Linus Torvalds
Status: Superseded by v6 (posted 2024-02-26). [go to v6]
Revision v3 (6 revisions archived).
Revisions (6)
Add an extra iflag to signify if the TRFCR register is accessible. Because TRBE requires FEAT_TRF, DEBUG_STATE_SAVE_TRBE still has the same behavior even though it's only set when FEAT_TRF is present. The following holes are left in struct kvm_vcpu_arch, but there aren't enough other 8 bit fields to rearrange it to leave any hole smaller than 7 bytes: u8 cflags; /* 2292 1 */ /* XXX 1 byte hole, try to pack */ u16 iflags; /* 2294 2 */ u8 sflags; /* 2296 1 */ bool pause; /* 2297 1 */ /* XXX 6 bytes hole, try to pack */ Signed-off-by: James Clark <redacted> --- arch/arm64/include/asm/kvm_host.h | 4 +++- arch/arm64/kvm/debug.c | 22 ++++++++++++++++++---- 2 files changed, 21 insertions(+), 5 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 7c82927ddaf2..0f0bf8e641bd 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h@@ -535,7 +535,7 @@ struct kvm_vcpu_arch { u8 cflags; /* Input flags to the hypervisor code, potentially cleared after use */ - u8 iflags; + u16 iflags; /* State flags for kernel bookkeeping, unused by the hypervisor code */ u8 sflags;
@@ -741,6 +741,8 @@ struct kvm_vcpu_arch { #define DEBUG_STATE_SAVE_TRBE __vcpu_single_flag(iflags, BIT(6)) /* vcpu running in HYP context */ #define VCPU_HYP_CONTEXT __vcpu_single_flag(iflags, BIT(7)) +/* Save trace filter controls */ +#define DEBUG_STATE_SAVE_TRFCR __vcpu_single_flag(iflags, BIT(8)) /* SVE enabled for host EL0 */ #define HOST_SVE_ENABLED __vcpu_single_flag(sflags, BIT(0))
diff --git a/arch/arm64/kvm/debug.c b/arch/arm64/kvm/debug.c
index 8725291cb00a..20cdd40b3c42 100644
--- a/arch/arm64/kvm/debug.c
+++ b/arch/arm64/kvm/debug.c@@ -331,14 +331,28 @@ void kvm_arch_vcpu_load_debug_state_flags(struct kvm_vcpu *vcpu) !(read_sysreg_s(SYS_PMBIDR_EL1) & BIT(PMBIDR_EL1_P_SHIFT))) vcpu_set_flag(vcpu, DEBUG_STATE_SAVE_SPE); - /* Check if we have TRBE implemented and available at the host */ - if (cpuid_feature_extract_unsigned_field(dfr0, ID_AA64DFR0_EL1_TraceBuffer_SHIFT) && - !(read_sysreg_s(SYS_TRBIDR_EL1) & TRBIDR_EL1_P)) - vcpu_set_flag(vcpu, DEBUG_STATE_SAVE_TRBE); + /* + * Save TRFCR on nVHE if FEAT_TRF (TraceFilt) exists. This will be + * done in cases where use of TRBE doesn't completely disable trace and + * handles the exclude_host/exclude_guest rules of the trace session. + */ + if (cpuid_feature_extract_unsigned_field(dfr0, ID_AA64DFR0_EL1_TraceFilt_SHIFT)) { + vcpu_set_flag(vcpu, DEBUG_STATE_SAVE_TRFCR); + /* + * Check if we have TRBE implemented and available at the host. If it's + * in use at the time of guest switch it will need to be disabled and + * then restored. The architecture mandates FEAT_TRF with TRBE, so we + * only need to check for TRBE after TRF. + */ + if (cpuid_feature_extract_unsigned_field(dfr0, ID_AA64DFR0_EL1_TraceBuffer_SHIFT) && + !(read_sysreg_s(SYS_TRBIDR_EL1) & TRBIDR_EL1_P)) + vcpu_set_flag(vcpu, DEBUG_STATE_SAVE_TRBE); + } } void kvm_arch_vcpu_put_debug_state_flags(struct kvm_vcpu *vcpu) { vcpu_clear_flag(vcpu, DEBUG_STATE_SAVE_SPE); vcpu_clear_flag(vcpu, DEBUG_STATE_SAVE_TRBE); + vcpu_clear_flag(vcpu, DEBUG_STATE_SAVE_TRFCR); }
--
2.34.1
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