From: Marc Zyngier <maz@kernel.org>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: kvm@vger.kernel.org, Quentin Perret <qperret@google.com>,
kernel-team@android.com,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Nick Desaulniers <ndesaulniers@google.com>,
James Morse <james.morse@arm.com>,
linux-arm-kernel@lists.infradead.org,
Nathan Chancellor <natechancellor@gmail.com>,
Will Deacon <will@kernel.org>,
kvmarm@lists.cs.columbia.edu,
Julien Thierry <julien.thierry.kdev@gmail.com>
Subject: [PATCH 1/2] KVM: arm64: Prevent vcpu_has_ptrauth from generating OOL functions
Date: Tue, 28 Jul 2020 09:22:54 +0100 [thread overview]
Message-ID: <20200728082255.3864378-2-maz@kernel.org> (raw)
In-Reply-To: <20200728082255.3864378-1-maz@kernel.org>
So far, vcpu_has_ptrauth() is implemented in terms of system_supports_*_auth()
calls, which are declared "inline". In some specific conditions (clang
and SCS), the "inline" very much turns into an "out of line", which
leads to a fireworks when this predicate is evaluated on a non-VHE
system (right at the beginning of __hyp_handle_ptrauth).
Instead, make sure vcpu_has_ptrauth gets expanded inline by directly
using the cpus_have_final_cap() helpers, which are __always_inline,
generate much better code, and are the only thing that make sense when
running at EL2 on a nVHE system.
Fixes: 29eb5a3c57f7 ("KVM: arm64: Handle PtrAuth traps early")
Reported-by: Nathan Chancellor <natechancellor@gmail.com>
Reported-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Link: https://lore.kernel.org/r/20200722162231.3689767-1-maz@kernel.org
---
arch/arm64/include/asm/kvm_host.h | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index c3e6fcc664b1..e21d4a01372f 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -380,9 +380,14 @@ struct kvm_vcpu_arch {
#define vcpu_has_sve(vcpu) (system_supports_sve() && \
((vcpu)->arch.flags & KVM_ARM64_GUEST_HAS_SVE))
-#define vcpu_has_ptrauth(vcpu) ((system_supports_address_auth() || \
- system_supports_generic_auth()) && \
- ((vcpu)->arch.flags & KVM_ARM64_GUEST_HAS_PTRAUTH))
+#ifdef CONFIG_ARM64_PTR_AUTH
+#define vcpu_has_ptrauth(vcpu) \
+ ((cpus_have_final_cap(ARM64_HAS_ADDRESS_AUTH) || \
+ cpus_have_final_cap(ARM64_HAS_GENERIC_AUTH)) && \
+ (vcpu)->arch.flags & KVM_ARM64_GUEST_HAS_PTRAUTH)
+#else
+#define vcpu_has_ptrauth(vcpu) false
+#endif
#define vcpu_gp_regs(v) (&(v)->arch.ctxt.gp_regs)
--
2.27.0
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next prev parent reply other threads:[~2020-07-28 8:24 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-28 8:22 [GIT PULL] KVM/arm64 fixes for 5.8, take #4 Marc Zyngier
2020-07-28 8:22 ` Marc Zyngier [this message]
2020-07-28 8:22 ` [PATCH 2/2] KVM: arm64: Don't inherit exec permission across page-table levels Marc Zyngier
2020-07-31 11:25 ` [GIT PULL] KVM/arm64 fixes for 5.8, take #4 Paolo Bonzini
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