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KVM: arm64: Reject 32bit user PSTATE on asymmetric systems

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[ Upstream commit b10d86fb8e46cc812171728bcd326df2f34e9ed5 ]

KVM does not support AArch32 EL0 on asymmetric systems. To that end,
prevent userspace from configuring a vCPU in such a state through
setting PSTATE.

It is already ABI that KVM rejects such a write on a system where
AArch32 EL0 is unsupported. Though the kernel's definition of a 32bit
system changed in commit 2122a833316f ("arm64: Allow mismatched
32-bit EL0 support"), KVM's did not.

Fixes: 2122a833316f ("arm64: Allow mismatched 32-bit EL0 support")
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220816192554.1455559-3-oliver.upton@linux.dev
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Oliver Upton 2022-08-16 19:25:54 +00:00 committed by Greg Kroah-Hartman
parent e4a36b051c
commit 62ef55aa43
1 changed files with 1 additions and 1 deletions
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2
arch/arm64/kvm/guest.c
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@ -242,7 +242,7 @@ static int set_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
u64 mode = (*(u64 *)valp) & PSR_AA32_MODE_MASK;
switch (mode) {
case PSR_AA32_MODE_USR:
if (!system_supports_32bit_el0())
if (!kvm_supports_32bit_el0())
return -EINVAL;
break;
case PSR_AA32_MODE_FIQ: