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From: Marc Zyngier <maz@kernel.org>
To: kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org,
	kvm@vger.kernel.org
Cc: James Morse <james.morse@arm.com>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	Oliver Upton <oliver.upton@linux.dev>,
	Zenghui Yu <yuzenghui@huawei.com>,
	James Clark <james.clark@arm.com>,
	Anshuman Khandual <anshuman.khandual@arm.com>
Subject: [PATCH] KVM: arm64: Fix TRFCR_EL1/PMSCR_EL1 access in hVHE mode
Date: Thu, 29 Feb 2024 14:54:17 +0000	[thread overview]
Message-ID: <20240229145417.3606279-1-maz@kernel.org> (raw)

When running in hVHE mode, EL1 accesses are performed with the EL12
accessor, as we run with HCR_EL2.E2H=1.

Unfortunately, both PMSCR_EL1 and TRFCR_EL1 are used with the
EL1 accessor, meaning that we actually affect the EL2 state. Duh.

Switch to using the {read,write}_sysreg_el1() helpers that will do
the right thing in all circumstances.

Note that the 'Fixes:' tag doesn't represent the point where the bug
was introduced (there is no such point), but the first practical point
where the hVHE feature is usable.

Cc: James Clark <james.clark@arm.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Fixes: 38cba55008e5 ("KVM: arm64: Force HCR_E2H in guest context when ARM64_KVM_HVHE is set")
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/kvm/hyp/nvhe/debug-sr.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/arch/arm64/kvm/hyp/nvhe/debug-sr.c b/arch/arm64/kvm/hyp/nvhe/debug-sr.c
index 8103f8c695b4..6d57b5c86a91 100644
--- a/arch/arm64/kvm/hyp/nvhe/debug-sr.c
+++ b/arch/arm64/kvm/hyp/nvhe/debug-sr.c
@@ -31,8 +31,8 @@ static void __debug_save_spe(u64 *pmscr_el1)
 		return;
 
 	/* Yes; save the control register and disable data generation */
-	*pmscr_el1 = read_sysreg_s(SYS_PMSCR_EL1);
-	write_sysreg_s(0, SYS_PMSCR_EL1);
+	*pmscr_el1 = read_sysreg_el1(SYS_PMSCR);
+	write_sysreg_el1(0, SYS_PMSCR);
 	isb();
 
 	/* Now drain all buffered data to memory */
@@ -48,7 +48,7 @@ static void __debug_restore_spe(u64 pmscr_el1)
 	isb();
 
 	/* Re-enable data generation */
-	write_sysreg_s(pmscr_el1, SYS_PMSCR_EL1);
+	write_sysreg_el1(pmscr_el1, SYS_PMSCR);
 }
 
 static void __debug_save_trace(u64 *trfcr_el1)
@@ -63,8 +63,8 @@ static void __debug_save_trace(u64 *trfcr_el1)
 	 * Since access to TRFCR_EL1 is trapped, the guest can't
 	 * modify the filtering set by the host.
 	 */
-	*trfcr_el1 = read_sysreg_s(SYS_TRFCR_EL1);
-	write_sysreg_s(0, SYS_TRFCR_EL1);
+	*trfcr_el1 = read_sysreg_el1(SYS_TRFCR);
+	write_sysreg_el1(0, SYS_TRFCR);
 	isb();
 	/* Drain the trace buffer to memory */
 	tsb_csync();
@@ -76,7 +76,7 @@ static void __debug_restore_trace(u64 trfcr_el1)
 		return;
 
 	/* Restore trace filter controls */
-	write_sysreg_s(trfcr_el1, SYS_TRFCR_EL1);
+	write_sysreg_el1(trfcr_el1, SYS_TRFCR);
 }
 
 void __debug_save_host_buffers_nvhe(struct kvm_vcpu *vcpu)
-- 
2.39.2


WARNING: multiple messages have this Message-ID (diff)
From: Marc Zyngier <maz@kernel.org>
To: kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org,
	kvm@vger.kernel.org
Cc: James Morse <james.morse@arm.com>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	Oliver Upton <oliver.upton@linux.dev>,
	Zenghui Yu <yuzenghui@huawei.com>,
	James Clark <james.clark@arm.com>,
	Anshuman Khandual <anshuman.khandual@arm.com>
Subject: [PATCH] KVM: arm64: Fix TRFCR_EL1/PMSCR_EL1 access in hVHE mode
Date: Thu, 29 Feb 2024 14:54:17 +0000	[thread overview]
Message-ID: <20240229145417.3606279-1-maz@kernel.org> (raw)

When running in hVHE mode, EL1 accesses are performed with the EL12
accessor, as we run with HCR_EL2.E2H=1.

Unfortunately, both PMSCR_EL1 and TRFCR_EL1 are used with the
EL1 accessor, meaning that we actually affect the EL2 state. Duh.

Switch to using the {read,write}_sysreg_el1() helpers that will do
the right thing in all circumstances.

Note that the 'Fixes:' tag doesn't represent the point where the bug
was introduced (there is no such point), but the first practical point
where the hVHE feature is usable.

Cc: James Clark <james.clark@arm.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Fixes: 38cba55008e5 ("KVM: arm64: Force HCR_E2H in guest context when ARM64_KVM_HVHE is set")
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/kvm/hyp/nvhe/debug-sr.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/arch/arm64/kvm/hyp/nvhe/debug-sr.c b/arch/arm64/kvm/hyp/nvhe/debug-sr.c
index 8103f8c695b4..6d57b5c86a91 100644
--- a/arch/arm64/kvm/hyp/nvhe/debug-sr.c
+++ b/arch/arm64/kvm/hyp/nvhe/debug-sr.c
@@ -31,8 +31,8 @@ static void __debug_save_spe(u64 *pmscr_el1)
 		return;
 
 	/* Yes; save the control register and disable data generation */
-	*pmscr_el1 = read_sysreg_s(SYS_PMSCR_EL1);
-	write_sysreg_s(0, SYS_PMSCR_EL1);
+	*pmscr_el1 = read_sysreg_el1(SYS_PMSCR);
+	write_sysreg_el1(0, SYS_PMSCR);
 	isb();
 
 	/* Now drain all buffered data to memory */
@@ -48,7 +48,7 @@ static void __debug_restore_spe(u64 pmscr_el1)
 	isb();
 
 	/* Re-enable data generation */
-	write_sysreg_s(pmscr_el1, SYS_PMSCR_EL1);
+	write_sysreg_el1(pmscr_el1, SYS_PMSCR);
 }
 
 static void __debug_save_trace(u64 *trfcr_el1)
@@ -63,8 +63,8 @@ static void __debug_save_trace(u64 *trfcr_el1)
 	 * Since access to TRFCR_EL1 is trapped, the guest can't
 	 * modify the filtering set by the host.
 	 */
-	*trfcr_el1 = read_sysreg_s(SYS_TRFCR_EL1);
-	write_sysreg_s(0, SYS_TRFCR_EL1);
+	*trfcr_el1 = read_sysreg_el1(SYS_TRFCR);
+	write_sysreg_el1(0, SYS_TRFCR);
 	isb();
 	/* Drain the trace buffer to memory */
 	tsb_csync();
@@ -76,7 +76,7 @@ static void __debug_restore_trace(u64 trfcr_el1)
 		return;
 
 	/* Restore trace filter controls */
-	write_sysreg_s(trfcr_el1, SYS_TRFCR_EL1);
+	write_sysreg_el1(trfcr_el1, SYS_TRFCR);
 }
 
 void __debug_save_host_buffers_nvhe(struct kvm_vcpu *vcpu)
-- 
2.39.2


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             reply	other threads:[~2024-02-29 14:54 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-02-29 14:54 Marc Zyngier [this message]
2024-02-29 14:54 ` [PATCH] KVM: arm64: Fix TRFCR_EL1/PMSCR_EL1 access in hVHE mode Marc Zyngier
2024-02-29 17:37 ` Oliver Upton
2024-02-29 17:37   ` Oliver Upton
2024-02-29 18:24   ` Marc Zyngier
2024-02-29 18:24     ` Marc Zyngier
2024-02-29 19:02     ` Oliver Upton
2024-02-29 19:02       ` Oliver Upton
2024-03-01 19:03 ` Oliver Upton
2024-03-01 19:03   ` Oliver Upton

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