From: James Clark <james.clark@arm.com>
To: coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org,
kvmarm@lists.linux.dev, maz@kernel.org, suzuki.poulose@arm.com,
acme@kernel.org, oliver.upton@linux.dev, broonie@kernel.org
Cc: James Clark <james.clark@arm.com>,
James Morse <james.morse@arm.com>,
Zenghui Yu <yuzenghui@huawei.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>, Mike Leach <mike.leach@linaro.org>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Anshuman Khandual <anshuman.khandual@arm.com>,
Miguel Luis <miguel.luis@oracle.com>,
Joey Gouly <joey.gouly@arm.com>, Ard Biesheuvel <ardb@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Arnd Bergmann <arnd@arndb.de>,
Javier Martinez Canillas <javierm@redhat.com>,
Vincent Donnefort <vdonnefort@google.com>,
Ryan Roberts <ryan.roberts@arm.com>,
Fuad Tabba <tabba@google.com>,
Jing Zhang <jingzhangos@google.com>,
linux-kernel@vger.kernel.org
Subject: [PATCH v5 4/7] arm64: KVM: Add iflag for FEAT_TRF
Date: Tue, 20 Feb 2024 10:09:14 +0000 [thread overview]
Message-ID: <20240220100924.2761706-5-james.clark@arm.com> (raw)
In-Reply-To: <20240220100924.2761706-1-james.clark@arm.com>
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 */
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: James Clark <james.clark@arm.com>
---
arch/arm64/include/asm/kvm_host.h | 4 +++-
arch/arm64/kvm/debug.c | 24 ++++++++++++++++++++----
2 files changed, 23 insertions(+), 5 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 21c57b812569..85b5477bd1b4 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -569,7 +569,7 @@ 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;
@@ -779,6 +779,8 @@ 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 ce8886122ed3..49a13e72ddd2 100644
--- a/arch/arm64/kvm/debug.c
+++ b/arch/arm64/kvm/debug.c
@@ -332,14 +332,30 @@ 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);
+ /*
+ * Set SAVE_TRFCR flag if FEAT_TRF (TraceFilt) exists. This flag
+ * signifies that the exclude_host/exclude_guest settings of any active
+ * host Perf session on a core running a VCPU can be written into
+ * TRFCR_EL1 on guest switch.
+ */
+ 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 then trace will
+ * need to be completely disabled. 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
next prev parent reply other threads:[~2024-02-20 10:10 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-02-20 10:09 [PATCH v5 0/7] kvm/coresight: Support exclude guest and exclude host James Clark
2024-02-20 10:09 ` [PATCH v5 1/7] arm64: KVM: Fix renamed function in comment James Clark
2024-02-20 10:09 ` [PATCH v5 2/7] arm64/sysreg/tools: Update tools copy of sysreg.h James Clark
2024-02-20 16:12 ` Mark Brown
2024-02-26 10:30 ` Suzuki K Poulose
2024-02-20 10:09 ` [PATCH v5 3/7] arm64/sysreg/tools: Move TRFCR definitions to sysreg James Clark
2024-02-20 16:11 ` Mark Brown
2024-02-21 10:10 ` James Clark
2024-02-21 12:56 ` Mark Brown
2024-02-20 10:09 ` James Clark [this message]
2024-02-20 10:09 ` [PATCH v5 5/7] arm64: KVM: Add interface to set guest value for TRFCR register James Clark
2024-02-23 10:03 ` Suzuki K Poulose
2024-02-23 16:39 ` James Clark
2024-02-26 9:52 ` Suzuki K Poulose
2024-02-26 11:36 ` James Clark
2024-02-20 10:09 ` [PATCH v5 6/7] arm64: KVM: Write TRFCR value on guest switch with nVHE James Clark
2024-02-26 10:14 ` Suzuki K Poulose
2024-02-20 10:09 ` [PATCH v5 7/7] coresight: Pass guest TRFCR value to KVM James Clark
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