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From: Marc Zyngier <maz@kernel.org>
To: <kvmarm@lists.cs.columbia.edu>, <kvmarm@lists.linux.dev>,
	kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org
Cc: James Morse <james.morse@arm.com>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	Alexandru Elisei <alexandru.elisei@arm.com>,
	Oliver Upton <oliver.upton@linux.dev>,
	Quentin Perret <qperret@google.com>,
	Will Deacon <will@kernel.org>, Fuad Tabba <tabba@google.com>
Subject: [PATCH 04/17] arm64: Prevent the use of is_kernel_in_hyp_mode() in hypervisor code
Date: Thu, 20 Oct 2022 10:07:14 +0100	[thread overview]
Message-ID: <20221020090727.3669908-5-maz@kernel.org> (raw)
In-Reply-To: <20221020090727.3669908-1-maz@kernel.org>

Using is_kernel_in_hyp_mode() in hypervisor code is a pretty bad
mistake. This helper only checks for CurrentEL being EL2, which
is always true.

Make the link fail if using the helper in hypervisor context
by referencing a non-existent function. Whilst we're at it,
flag the helper as __always_inline, which it really should be.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/include/asm/virt.h | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/include/asm/virt.h b/arch/arm64/include/asm/virt.h
index b11a1c8c8b36..5f84a87a6a2d 100644
--- a/arch/arm64/include/asm/virt.h
+++ b/arch/arm64/include/asm/virt.h
@@ -110,8 +110,13 @@ static inline bool is_hyp_mode_mismatched(void)
 	return __boot_cpu_mode[0] != __boot_cpu_mode[1];
 }
 
-static inline bool is_kernel_in_hyp_mode(void)
+extern void gotcha_is_kernel_in_hyp_mode(void);
+
+static __always_inline bool is_kernel_in_hyp_mode(void)
 {
+#if defined(__KVM_NVHE_HYPERVISOR__) || defined(__KVM_VHE_HYPERVISOR__)
+	gotcha_is_kernel_in_hyp_mode();
+#endif
 	return read_sysreg(CurrentEL) == CurrentEL_EL2;
 }
 
-- 
2.34.1


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  parent reply	other threads:[~2022-10-20  9:09 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-10-20  9:07 [PATCH 00/17] KVM: arm64: Allow using VHE in the nVHE hypervisor Marc Zyngier
2022-10-20  9:07 ` [PATCH 01/17] arm64: Turn kaslr_feature_override into a generic SW feature override Marc Zyngier
2022-10-20  9:07 ` [PATCH 02/17] arm64: Add KVM_HVHE capability and has_hvhe() predicate Marc Zyngier
2023-06-01  7:01   ` Oliver Upton
2022-10-20  9:07 ` [PATCH 03/17] arm64: Don't enable VHE for the kernel if OVERRIDE_HVHE is set Marc Zyngier
2022-10-20  9:07 ` Marc Zyngier [this message]
2022-10-20  9:07 ` [PATCH 05/17] arm64: Allow EL1 physical timer access when running VHE Marc Zyngier
2022-10-20  9:07 ` [PATCH 06/17] arm64: Use CPACR_EL1 format to set CPTR_EL2 when E2H is set Marc Zyngier
2022-10-20  9:07 ` [PATCH 07/17] KVM: arm64: Elide kern_hyp_va() in VHE-specific parts of the hypervisor Marc Zyngier
2022-10-20  9:07 ` [PATCH 08/17] KVM: arm64: Remove alternatives from sysreg accessors in VHE hypervisor context Marc Zyngier
2022-10-20  9:07 ` [PATCH 09/17] KVM: arm64: Key use of VHE instructions in nVHE code off ARM64_KVM_HVHE Marc Zyngier
2022-10-20  9:07 ` [PATCH 10/17] KVM: arm64: Force HCR_EL2.E2H when ARM64_KVM_HVHE is set Marc Zyngier
2022-10-20  9:07 ` [PATCH 11/17] KVM: arm64: Disable TTBR1_EL2 when using ARM64_KVM_HVHE Marc Zyngier
2022-10-20  9:07 ` [PATCH 12/17] KVM: arm64: Adjust EL2 stage-1 leaf AP bits when ARM64_KVM_HVHE is set Marc Zyngier
2022-10-20  9:07 ` [PATCH 13/17] KVM: arm64: Rework CPTR_EL2 programming for HVHE configuration Marc Zyngier
2022-10-20  9:07 ` [PATCH 14/17] KVM: arm64: Program the timer traps with VHE layout in hVHE mode Marc Zyngier
2022-10-20  9:07 ` [PATCH 15/17] KVM: arm64: Force HCR_E2H in guest context when ARM64_KVM_HVHE is set Marc Zyngier
2022-10-20  9:07 ` [PATCH 16/17] arm64: Allow arm64_sw.hvhe on command line Marc Zyngier
2022-10-20  9:07 ` [PATCH 17/17] KVM: arm64: Terrible timer hack for M1 with hVHE Marc Zyngier

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