[PATCH v4 10/28] KVM: arm64: Correctly handle ACCDATA_EL1 traps

From: Marc Zyngier <maz@kernel.org>
To: kvmarm@lists.linux.dev, kvm@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org
Cc: Catalin Marinas <catalin.marinas@arm.com>,
	Eric Auger <eric.auger@redhat.com>,
	Mark Brown <broonie@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Will Deacon <will@kernel.org>,
	Alexandru Elisei <alexandru.elisei@arm.com>,
	Andre Przywara <andre.przywara@arm.com>,
	Chase Conklin <chase.conklin@arm.com>,
	Ganapatrao Kulkarni <gankulkarni@os.amperecomputing.com>,
	Darren Hart <darren@os.amperecomputing.com>,
	Miguel Luis <miguel.luis@oracle.com>,
	Jing Zhang <jingzhangos@google.com>,
	James Morse <james.morse@arm.com>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	Oliver Upton <oliver.upton@linux.dev>,
	Zenghui Yu <yuzenghui@huawei.com>
Subject: [PATCH v4 10/28] KVM: arm64: Correctly handle ACCDATA_EL1 traps
Date: Tue, 15 Aug 2023 19:38:44 +0100	[thread overview]
Message-ID: <20230815183903.2735724-11-maz@kernel.org> (raw)
In-Reply-To: <20230815183903.2735724-1-maz@kernel.org>

As we blindly reset some HFGxTR_EL2 bits to 0, we also randomly trap
unsuspecting sysregs that have their trap bits with a negative
polarity.

ACCDATA_EL1 is one such register that can be accessed by the guest,
causing a splat on the host as we don't have a proper handler for
it.

Adding such handler addresses the issue, though there are a number
of other registers missing as the current architecture documentation
doesn't describe them yet.

Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Miguel Luis <miguel.luis@oracle.com>
Reviewed-by: Jing Zhang <jingzhangos@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/include/asm/sysreg.h | 2 ++
 arch/arm64/kvm/sys_regs.c       | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h
index 043c677e9f04..818c111009ca 100644
--- a/arch/arm64/include/asm/sysreg.h
+++ b/arch/arm64/include/asm/sysreg.h
@@ -387,6 +387,8 @@
 #define SYS_ICC_IGRPEN0_EL1		sys_reg(3, 0, 12, 12, 6)
 #define SYS_ICC_IGRPEN1_EL1		sys_reg(3, 0, 12, 12, 7)
 
+#define SYS_ACCDATA_EL1			sys_reg(3, 0, 13, 0, 5)
+
 #define SYS_CNTKCTL_EL1			sys_reg(3, 0, 14, 1, 0)
 
 #define SYS_AIDR_EL1			sys_reg(3, 1, 0, 0, 7)
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 2ca2973abe66..38f221f9fc98 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -2151,6 +2151,8 @@ static const struct sys_reg_desc sys_reg_descs[] = {
 	{ SYS_DESC(SYS_CONTEXTIDR_EL1), access_vm_reg, reset_val, CONTEXTIDR_EL1, 0 },
 	{ SYS_DESC(SYS_TPIDR_EL1), NULL, reset_unknown, TPIDR_EL1 },
 
+	{ SYS_DESC(SYS_ACCDATA_EL1), undef_access },
+
 	{ SYS_DESC(SYS_SCXTNUM_EL1), undef_access },
 
 	{ SYS_DESC(SYS_CNTKCTL_EL1), NULL, reset_val, CNTKCTL_EL1, 0},
-- 
2.34.1


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