From: Jing Zhang <jingzhangos@google.com>
To: KVM <kvm@vger.kernel.org>, KVMARM <kvmarm@lists.linux.dev>,
ARMLinux <linux-arm-kernel@lists.infradead.org>,
Marc Zyngier <maz@kernel.org>,
Oliver Upton <oliver.upton@linux.dev>
Cc: Will Deacon <will@kernel.org>,
Paolo Bonzini <pbonzini@redhat.com>,
James Morse <james.morse@arm.com>,
Alexandru Elisei <alexandru.elisei@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Fuad Tabba <tabba@google.com>,
Reiji Watanabe <reijiw@google.com>,
Raghavendra Rao Ananta <rananta@google.com>,
Suraj Jitindar Singh <surajjs@amazon.com>,
Cornelia Huck <cohuck@redhat.com>,
Jing Zhang <jingzhangos@google.com>
Subject: [PATCH v5 3/6] KVM: arm64: Reject attempts to set invalid debug arch version
Date: Mon, 10 Jul 2023 19:24:26 +0000 [thread overview]
Message-ID: <20230710192430.1992246-4-jingzhangos@google.com> (raw)
In-Reply-To: <20230710192430.1992246-1-jingzhangos@google.com>
From: Oliver Upton <oliver.upton@linux.dev>
The debug architecture is mandatory in ARMv8, so KVM should not allow
userspace to configure a vCPU with less than that. Of course, this isn't
handled elegantly by the generic ID register plumbing, as the respective
ID register fields have a nonzero starting value.
Add an explicit check for debug versions less than v8 of the
architecture.
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Jing Zhang <jingzhangos@google.com>
---
arch/arm64/kvm/sys_regs.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 0160ef9cfe18..c44504038ae9 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -1496,6 +1496,7 @@ static int set_id_aa64dfr0_el1(struct kvm_vcpu *vcpu,
const struct sys_reg_desc *rd,
u64 val)
{
+ u8 debugver = SYS_FIELD_GET(ID_AA64DFR0_EL1, DebugVer, val);
u8 pmuver = SYS_FIELD_GET(ID_AA64DFR0_EL1, PMUVer, val);
/*
@@ -1515,6 +1516,13 @@ static int set_id_aa64dfr0_el1(struct kvm_vcpu *vcpu,
if (pmuver == ID_AA64DFR0_EL1_PMUVer_IMP_DEF)
val &= ~ID_AA64DFR0_EL1_PMUVer_MASK;
+ /*
+ * ID_AA64DFR0_EL1.DebugVer is one of those awkward fields with a
+ * nonzero minimum safe value.
+ */
+ if (debugver < ID_AA64DFR0_EL1_DebugVer_IMP)
+ return -EINVAL;
+
return set_id_reg(vcpu, rd, val);
}
@@ -1536,6 +1544,7 @@ static int set_id_dfr0_el1(struct kvm_vcpu *vcpu,
u64 val)
{
u8 perfmon = SYS_FIELD_GET(ID_DFR0_EL1, PerfMon, val);
+ u8 copdbg = SYS_FIELD_GET(ID_DFR0_EL1, CopDbg, val);
if (perfmon == ID_DFR0_EL1_PerfMon_IMPDEF) {
val &= ~ID_DFR0_EL1_PerfMon_MASK;
@@ -1551,6 +1560,9 @@ static int set_id_dfr0_el1(struct kvm_vcpu *vcpu,
if (perfmon != 0 && perfmon < ID_DFR0_EL1_PerfMon_PMUv3)
return -EINVAL;
+ if (copdbg < ID_DFR0_EL1_CopDbg_Armv8)
+ return -EINVAL;
+
return set_id_reg(vcpu, rd, val);
}
--
2.41.0.255.g8b1d071c50-goog
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next prev parent reply other threads:[~2023-07-10 19:25 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-10 19:24 [PATCH v5 0/6] Enable writable for idregs DFR0,PFR0, MMFR{0,1,2, 3} Jing Zhang
2023-07-10 19:24 ` [PATCH v5 1/6] KVM: arm64: Use guest ID register values for the sake of emulation Jing Zhang
2023-07-10 19:24 ` [PATCH v5 2/6] KVM: arm64: Enable writable for ID_AA64DFR0_EL1 and ID_DFR0_EL1 Jing Zhang
2023-07-10 19:24 ` Jing Zhang [this message]
2023-07-10 20:18 ` [PATCH v5 3/6] KVM: arm64: Reject attempts to set invalid debug arch version Oliver Upton
2023-07-10 20:54 ` Jing Zhang
2023-07-10 19:24 ` [PATCH v5 4/6] KVM: arm64: Enable writable for ID_AA64PFR0_EL1 Jing Zhang
2023-07-10 19:24 ` [PATCH v5 5/6] KVM: arm64: Enable writable for ID_AA64MMFR{0, 1, 2, 3}_EL1 Jing Zhang
2023-07-10 19:24 ` [PATCH v5 6/6] KVM: arm64: selftests: Test for setting ID register from usersapce Jing Zhang
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