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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>,
	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,
	Peter Shier <pshier@google.com>,
	Ricardo Koller <ricarkol@google.com>,
	Reiji Watanabe <reijiw@google.com>,
	Paolo Bonzini <pbonzini@redhat.com>,
	Will Deacon <will@kernel.org>, Oliver Upton <oupton@google.com>
Subject: [PATCH v2 2/3] KVM: arm64: Actually prevent SMC64 SYSTEM_RESET2 from AArch32
Date: Tue, 22 Mar 2022 18:35:37 +0000	[thread overview]
Message-ID: <20220322183538.2757758-3-oupton@google.com> (raw)
In-Reply-To: <20220322183538.2757758-1-oupton@google.com>

The SMCCC does not allow the SMC64 calling convention to be used from
AArch32. While KVM checks to see if the calling convention is allowed in
PSCI_1_0_FN_PSCI_FEATURES, it does not actually prevent calls to
unadvertised PSCI v1.0+ functions.

Hoist the check to see if the requested function is allowed into
kvm_psci_call(), thereby preventing SMC64 calls from AArch32 for all
PSCI versions.

Fixes: d43583b890e7 ("KVM: arm64: Expose PSCI SYSTEM_RESET2 call to the guest")
Acked-by: Will Deacon <will@kernel.org>
Reviewed-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Oliver Upton <oupton@google.com>
---
 arch/arm64/kvm/psci.c | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/arch/arm64/kvm/psci.c b/arch/arm64/kvm/psci.c
index cd3ee947485f..d24ccc77500b 100644
--- a/arch/arm64/kvm/psci.c
+++ b/arch/arm64/kvm/psci.c
@@ -232,10 +232,6 @@ static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu)
 	unsigned long val;
 	int ret = 1;
 
-	val = kvm_psci_check_allowed_function(vcpu, psci_fn);
-	if (val)
-		goto out;
-
 	switch (psci_fn) {
 	case PSCI_0_2_FN_PSCI_VERSION:
 		/*
@@ -303,7 +299,6 @@ static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu)
 		break;
 	}
 
-out:
 	smccc_set_retval(vcpu, val, 0, 0, 0);
 	return ret;
 }
@@ -423,6 +418,15 @@ static int kvm_psci_0_1_call(struct kvm_vcpu *vcpu)
  */
 int kvm_psci_call(struct kvm_vcpu *vcpu)
 {
+	u32 psci_fn = smccc_get_function(vcpu);
+	unsigned long val;
+
+	val = kvm_psci_check_allowed_function(vcpu, psci_fn);
+	if (val) {
+		smccc_set_retval(vcpu, val, 0, 0, 0);
+		return 1;
+	}
+
 	switch (kvm_psci_version(vcpu)) {
 	case KVM_ARM_PSCI_1_1:
 		return kvm_psci_1_x_call(vcpu, 1);
-- 
2.35.1.894.gb6a874cedc-goog


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, Will Deacon <will@kernel.org>,
	Marc Zyngier <maz@kernel.org>, Peter Shier <pshier@google.com>,
	Paolo Bonzini <pbonzini@redhat.com>,
	linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2 2/3] KVM: arm64: Actually prevent SMC64 SYSTEM_RESET2 from AArch32
Date: Tue, 22 Mar 2022 18:35:37 +0000	[thread overview]
Message-ID: <20220322183538.2757758-3-oupton@google.com> (raw)
In-Reply-To: <20220322183538.2757758-1-oupton@google.com>

The SMCCC does not allow the SMC64 calling convention to be used from
AArch32. While KVM checks to see if the calling convention is allowed in
PSCI_1_0_FN_PSCI_FEATURES, it does not actually prevent calls to
unadvertised PSCI v1.0+ functions.

Hoist the check to see if the requested function is allowed into
kvm_psci_call(), thereby preventing SMC64 calls from AArch32 for all
PSCI versions.

Fixes: d43583b890e7 ("KVM: arm64: Expose PSCI SYSTEM_RESET2 call to the guest")
Acked-by: Will Deacon <will@kernel.org>
Reviewed-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Oliver Upton <oupton@google.com>
---
 arch/arm64/kvm/psci.c | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/arch/arm64/kvm/psci.c b/arch/arm64/kvm/psci.c
index cd3ee947485f..d24ccc77500b 100644
--- a/arch/arm64/kvm/psci.c
+++ b/arch/arm64/kvm/psci.c
@@ -232,10 +232,6 @@ static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu)
 	unsigned long val;
 	int ret = 1;
 
-	val = kvm_psci_check_allowed_function(vcpu, psci_fn);
-	if (val)
-		goto out;
-
 	switch (psci_fn) {
 	case PSCI_0_2_FN_PSCI_VERSION:
 		/*
@@ -303,7 +299,6 @@ static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu)
 		break;
 	}
 
-out:
 	smccc_set_retval(vcpu, val, 0, 0, 0);
 	return ret;
 }
@@ -423,6 +418,15 @@ static int kvm_psci_0_1_call(struct kvm_vcpu *vcpu)
  */
 int kvm_psci_call(struct kvm_vcpu *vcpu)
 {
+	u32 psci_fn = smccc_get_function(vcpu);
+	unsigned long val;
+
+	val = kvm_psci_check_allowed_function(vcpu, psci_fn);
+	if (val) {
+		smccc_set_retval(vcpu, val, 0, 0, 0);
+		return 1;
+	}
+
 	switch (kvm_psci_version(vcpu)) {
 	case KVM_ARM_PSCI_1_1:
 		return kvm_psci_1_x_call(vcpu, 1);
-- 
2.35.1.894.gb6a874cedc-goog

_______________________________________________
kvmarm mailing list
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,
	Peter Shier <pshier@google.com>,
	 Ricardo Koller <ricarkol@google.com>,
	Reiji Watanabe <reijiw@google.com>,
	 Paolo Bonzini <pbonzini@redhat.com>,
	Will Deacon <will@kernel.org>, Oliver Upton <oupton@google.com>
Subject: [PATCH v2 2/3] KVM: arm64: Actually prevent SMC64 SYSTEM_RESET2 from AArch32
Date: Tue, 22 Mar 2022 18:35:37 +0000	[thread overview]
Message-ID: <20220322183538.2757758-3-oupton@google.com> (raw)
In-Reply-To: <20220322183538.2757758-1-oupton@google.com>

The SMCCC does not allow the SMC64 calling convention to be used from
AArch32. While KVM checks to see if the calling convention is allowed in
PSCI_1_0_FN_PSCI_FEATURES, it does not actually prevent calls to
unadvertised PSCI v1.0+ functions.

Hoist the check to see if the requested function is allowed into
kvm_psci_call(), thereby preventing SMC64 calls from AArch32 for all
PSCI versions.

Fixes: d43583b890e7 ("KVM: arm64: Expose PSCI SYSTEM_RESET2 call to the guest")
Acked-by: Will Deacon <will@kernel.org>
Reviewed-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Oliver Upton <oupton@google.com>
---
 arch/arm64/kvm/psci.c | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/arch/arm64/kvm/psci.c b/arch/arm64/kvm/psci.c
index cd3ee947485f..d24ccc77500b 100644
--- a/arch/arm64/kvm/psci.c
+++ b/arch/arm64/kvm/psci.c
@@ -232,10 +232,6 @@ static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu)
 	unsigned long val;
 	int ret = 1;
 
-	val = kvm_psci_check_allowed_function(vcpu, psci_fn);
-	if (val)
-		goto out;
-
 	switch (psci_fn) {
 	case PSCI_0_2_FN_PSCI_VERSION:
 		/*
@@ -303,7 +299,6 @@ static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu)
 		break;
 	}
 
-out:
 	smccc_set_retval(vcpu, val, 0, 0, 0);
 	return ret;
 }
@@ -423,6 +418,15 @@ static int kvm_psci_0_1_call(struct kvm_vcpu *vcpu)
  */
 int kvm_psci_call(struct kvm_vcpu *vcpu)
 {
+	u32 psci_fn = smccc_get_function(vcpu);
+	unsigned long val;
+
+	val = kvm_psci_check_allowed_function(vcpu, psci_fn);
+	if (val) {
+		smccc_set_retval(vcpu, val, 0, 0, 0);
+		return 1;
+	}
+
 	switch (kvm_psci_version(vcpu)) {
 	case KVM_ARM_PSCI_1_1:
 		return kvm_psci_1_x_call(vcpu, 1);
-- 
2.35.1.894.gb6a874cedc-goog


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

  parent reply	other threads:[~2022-03-22 18:35 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-03-22 18:35 [PATCH v2 0/3] KVM: arm64: Fixes for SMC64 SYSTEM_RESET2 calls Oliver Upton
2022-03-22 18:35 ` Oliver Upton
2022-03-22 18:35 ` Oliver Upton
2022-03-22 18:35 ` [PATCH v2 1/3] KVM: arm64: Generally disallow SMC64 for AArch32 guests Oliver Upton
2022-03-22 18:35   ` Oliver Upton
2022-03-22 18:35   ` Oliver Upton
2022-03-22 18:35 ` Oliver Upton [this message]
2022-03-22 18:35   ` [PATCH v2 2/3] KVM: arm64: Actually prevent SMC64 SYSTEM_RESET2 from AArch32 Oliver Upton
2022-03-22 18:35   ` Oliver Upton
2022-03-22 18:35 ` [PATCH v2 3/3] KVM: arm64: Drop unneeded minor version check from PSCI v1.x handler Oliver Upton
2022-03-22 18:35   ` Oliver Upton
2022-03-22 18:35   ` Oliver Upton
2022-03-23  9:26 ` [PATCH v2 0/3] KVM: arm64: Fixes for SMC64 SYSTEM_RESET2 calls Marc Zyngier
2022-03-23  9:26   ` Marc Zyngier
2022-03-23  9:26   ` Marc Zyngier

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