[PATCH v2 1/6] KVM: arm64: Correctly treat writes to OSLSR_EL1 as undefined

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From: Oliver Upton <oupton@google.com>
To: kvmarm@lists.cs.columbia.edu
Cc: kvm@vger.kernel.org, Marc Zyngier <maz@kernel.org>,
	Peter Shier <pshier@google.com>,
	linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2 1/6] KVM: arm64: Correctly treat writes to OSLSR_EL1 as undefined
Date: Tue,  2 Nov 2021 09:46:46 +0000	[thread overview]
Message-ID: <20211102094651.2071532-2-oupton@google.com> (raw)
In-Reply-To: <20211102094651.2071532-1-oupton@google.com>

Any valid implementation of the architecture should generate an
undefined exception for writes to a read-only register, such as
OSLSR_EL1. Nonetheless, the KVM handler actually implements write-ignore
behavior.

Align the trap handler for OSLSR_EL1 with hardware behavior. If such a
write ever traps to EL2, inject an undef into the guest and print a
warning.

Signed-off-by: Oliver Upton <oupton@google.com>
---
 arch/arm64/kvm/sys_regs.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 1d46e185f31e..17fa6ddf5405 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -292,7 +292,7 @@ static bool trap_oslsr_el1(struct kvm_vcpu *vcpu,
 			   const struct sys_reg_desc *r)
 {
 	if (p->is_write) {
-		return ignore_write(vcpu, p);
+		return write_to_read_only(vcpu, p, r);
 	} else {
 		p->regval = (1 << 3);
 		return true;
-- 
2.33.1.1089.g2158813163f-goog

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kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

WARNING: multiple messages have this Message-ID (diff)

From: Oliver Upton <oupton@google.com>
To: kvmarm@lists.cs.columbia.edu
Cc: kvm@vger.kernel.org, Marc Zyngier <maz@kernel.org>,
	James Morse <james.morse@arm.com>,
	 Alexandru Elisei <alexandru.elisei@arm.com>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	 linux-arm-kernel@lists.infradead.org,
	Andrew Jones <drjones@redhat.com>,
	 Peter Shier <pshier@google.com>,
	Ricardo Koller <ricarkol@google.com>,
	 Reiji Watanabe <reijiw@google.com>,
	Oliver Upton <oupton@google.com>
Subject: [PATCH v2 1/6] KVM: arm64: Correctly treat writes to OSLSR_EL1 as undefined
Date: Tue,  2 Nov 2021 09:46:46 +0000	[thread overview]
Message-ID: <20211102094651.2071532-2-oupton@google.com> (raw)
In-Reply-To: <20211102094651.2071532-1-oupton@google.com>

Any valid implementation of the architecture should generate an
undefined exception for writes to a read-only register, such as
OSLSR_EL1. Nonetheless, the KVM handler actually implements write-ignore
behavior.

Align the trap handler for OSLSR_EL1 with hardware behavior. If such a
write ever traps to EL2, inject an undef into the guest and print a
warning.

Signed-off-by: Oliver Upton <oupton@google.com>
---
 arch/arm64/kvm/sys_regs.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 1d46e185f31e..17fa6ddf5405 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -292,7 +292,7 @@ static bool trap_oslsr_el1(struct kvm_vcpu *vcpu,
 			   const struct sys_reg_desc *r)
 {
 	if (p->is_write) {
-		return ignore_write(vcpu, p);
+		return write_to_read_only(vcpu, p, r);
 	} else {
 		p->regval = (1 << 3);
 		return true;
-- 
2.33.1.1089.g2158813163f-goog


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

WARNING: multiple messages have this Message-ID (diff)

From: Oliver Upton <oupton@google.com>
To: kvmarm@lists.cs.columbia.edu
Cc: kvm@vger.kernel.org, Marc Zyngier <maz@kernel.org>,
	James Morse <james.morse@arm.com>,
	Alexandru Elisei <alexandru.elisei@arm.com>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	linux-arm-kernel@lists.infradead.org,
	Andrew Jones <drjones@redhat.com>,
	Peter Shier <pshier@google.com>,
	Ricardo Koller <ricarkol@google.com>,
	Reiji Watanabe <reijiw@google.com>,
	Oliver Upton <oupton@google.com>
Subject: [PATCH v2 1/6] KVM: arm64: Correctly treat writes to OSLSR_EL1 as undefined
Date: Tue,  2 Nov 2021 09:46:46 +0000	[thread overview]
Message-ID: <20211102094651.2071532-2-oupton@google.com> (raw)
In-Reply-To: <20211102094651.2071532-1-oupton@google.com>

Any valid implementation of the architecture should generate an
undefined exception for writes to a read-only register, such as
OSLSR_EL1. Nonetheless, the KVM handler actually implements write-ignore
behavior.

Align the trap handler for OSLSR_EL1 with hardware behavior. If such a
write ever traps to EL2, inject an undef into the guest and print a
warning.

Signed-off-by: Oliver Upton <oupton@google.com>
---
 arch/arm64/kvm/sys_regs.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 1d46e185f31e..17fa6ddf5405 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -292,7 +292,7 @@ static bool trap_oslsr_el1(struct kvm_vcpu *vcpu,
 			   const struct sys_reg_desc *r)
 {
 	if (p->is_write) {
-		return ignore_write(vcpu, p);
+		return write_to_read_only(vcpu, p, r);
 	} else {
 		p->regval = (1 << 3);
 		return true;
-- 
2.33.1.1089.g2158813163f-goog

next prev parent reply	other threads:[~2021-11-02  9:47 UTC|newest]

Thread overview: 66+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-11-02  9:46 [PATCH v2 0/6] KVM: arm64: Emulate the OS lock Oliver Upton
2021-11-02  9:46 ` Oliver Upton
2021-11-02  9:46 ` Oliver Upton
2021-11-02  9:46 ` Oliver Upton [this message]
2021-11-02  9:46   ` [PATCH v2 1/6] KVM: arm64: Correctly treat writes to OSLSR_EL1 as undefined Oliver Upton
2021-11-02  9:46   ` Oliver Upton
2021-11-04  2:40   ` Reiji Watanabe
2021-11-04  2:40     ` Reiji Watanabe
2021-11-04  2:40     ` Reiji Watanabe
2021-11-02  9:46 ` [PATCH v2 2/6] KVM: arm64: Stash OSLSR_EL1 in the cpu context Oliver Upton
2021-11-02  9:46   ` Oliver Upton
2021-11-02  9:46   ` Oliver Upton
2021-11-02  9:51   ` Oliver Upton
2021-11-02  9:51     ` Oliver Upton
2021-11-02  9:51     ` Oliver Upton
2021-11-04  3:37     ` Reiji Watanabe
2021-11-04  3:37       ` Reiji Watanabe
2021-11-04  3:37       ` Reiji Watanabe
2021-11-02  9:46 ` [PATCH v2 3/6] KVM: arm64: Allow guest to set the OSLK bit Oliver Upton
2021-11-02  9:46   ` Oliver Upton
2021-11-02  9:46   ` Oliver Upton
2021-11-04  3:31   ` Reiji Watanabe
2021-11-04  3:31     ` Reiji Watanabe
2021-11-04  3:31     ` Reiji Watanabe
2021-11-04  3:47     ` Ricardo Koller
2021-11-04  3:47       ` Ricardo Koller
2021-11-04  3:47       ` Ricardo Koller
2021-11-04  4:40       ` Oliver Upton
2021-11-04  4:40         ` Oliver Upton
2021-11-04  4:40         ` Oliver Upton
2021-11-02  9:46 ` [PATCH v2 4/6] KVM: arm64: Emulate the OS Lock Oliver Upton
2021-11-02  9:46   ` Oliver Upton
2021-11-02  9:46   ` Oliver Upton
2021-11-02 23:45   ` Ricardo Koller
2021-11-02 23:45     ` Ricardo Koller
2021-11-02 23:45     ` Ricardo Koller
2021-11-03  0:35     ` Oliver Upton
2021-11-03  0:35       ` Oliver Upton
2021-11-03  0:35       ` Oliver Upton
2021-11-05  3:56   ` Reiji Watanabe
2021-11-05  3:56     ` Reiji Watanabe
2021-11-05  3:56     ` Reiji Watanabe
2021-11-05  5:36     ` Oliver Upton
2021-11-05  5:36       ` Oliver Upton
2021-11-05  5:36       ` Oliver Upton
2021-11-02  9:46 ` [PATCH v2 5/6] selftests: KVM: Add OSLSR_EL1 to the list of blessed regs Oliver Upton
2021-11-02  9:46   ` Oliver Upton
2021-11-02  9:46   ` Oliver Upton
2021-11-02  9:46 ` [PATCH v2 6/6] selftests: KVM: Test OS lock behavior Oliver Upton
2021-11-02  9:46   ` Oliver Upton
2021-11-02  9:46   ` Oliver Upton
2021-11-02 11:09   ` Marc Zyngier
2021-11-02 11:09     ` Marc Zyngier
2021-11-02 11:09     ` Marc Zyngier
2021-11-02 14:53     ` Oliver Upton
2021-11-02 14:53       ` Oliver Upton
2021-11-02 14:53       ` Oliver Upton
2021-11-02 20:01       ` Oliver Upton
2021-11-02 20:01         ` Oliver Upton
2021-11-02 20:01         ` Oliver Upton
2021-11-02 23:27   ` Ricardo Koller
2021-11-02 23:27     ` Ricardo Koller
2021-11-02 23:27     ` Ricardo Koller
2021-11-02 23:36     ` Oliver Upton
2021-11-02 23:36       ` Oliver Upton
2021-11-02 23:36       ` Oliver Upton

find likely ancestor, descendant, or conflicting patches for this message:
( dfblob:1d46e185f31 dfblob:17fa6ddf540 dfblob:1d46e185f31
dfblob:17fa6ddf540 dfblob:1d46e185f31 dfblob:17fa6ddf540 )
 OR (
bs:"[PATCH v2 1/6] KVM: arm64: Correctly treat writes to OSLSR_EL1 as undefined" )
	(help)

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