From: Marc Zyngier <maz@kernel.org>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: James Morse <james.morse@arm.com>,
Jeremy Cline <jcline@redhat.com>,
Mark Rutland <mark.rutland@arm.com>,
Will Deacon <will@kernel.org>,
Julien Thierry <julien.thierry.kdev@gmail.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org,
linux-arm-kernel@lists.infradead.org
Subject: [PATCH 4/5] KVM: arm64: Define our own swab32() to avoid a uapi static inline
Date: Tue, 25 Feb 2020 23:52:22 +0000 [thread overview]
Message-ID: <20200225235223.12839-5-maz@kernel.org> (raw)
In-Reply-To: <20200225235223.12839-1-maz@kernel.org>
From: James Morse <james.morse@arm.com>
KVM uses swab32() when mediating GIC MMIO accesses if the GICV is badly
aligned, and the host and guest differ in endianness.
arm64 doesn't provide a __arch_swab32(), so __fswab32() is always backed
by the macro implementation that the compiler reduces to a single
instruction. But the static-inline causes problems for KVM if the compiler
chooses not to inline this function, it may not be located in the
__hyp_text where __vgic_v2_perform_cpuif_access() needs it.
Create our own __kvm_swab32() macro that calls ___constant_swab32()
directly. This way we know it will always be inlined.
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200220165839.256881-3-james.morse@arm.com
---
arch/arm64/include/asm/kvm_hyp.h | 7 +++++++
arch/arm64/kvm/hyp/vgic-v2-cpuif-proxy.c | 4 ++--
2 files changed, 9 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_hyp.h b/arch/arm64/include/asm/kvm_hyp.h
index 97f21cc66657..5fde137b5150 100644
--- a/arch/arm64/include/asm/kvm_hyp.h
+++ b/arch/arm64/include/asm/kvm_hyp.h
@@ -47,6 +47,13 @@
#define read_sysreg_el2(r) read_sysreg_elx(r, _EL2, _EL1)
#define write_sysreg_el2(v,r) write_sysreg_elx(v, r, _EL2, _EL1)
+/*
+ * Without an __arch_swab32(), we fall back to ___constant_swab32(), but the
+ * static inline can allow the compiler to out-of-line this. KVM always wants
+ * the macro version as its always inlined.
+ */
+#define __kvm_swab32(x) ___constant_swab32(x)
+
int __vgic_v2_perform_cpuif_access(struct kvm_vcpu *vcpu);
void __vgic_v3_save_state(struct kvm_vcpu *vcpu);
diff --git a/arch/arm64/kvm/hyp/vgic-v2-cpuif-proxy.c b/arch/arm64/kvm/hyp/vgic-v2-cpuif-proxy.c
index 29ee1feba4eb..4f3a087e36d5 100644
--- a/arch/arm64/kvm/hyp/vgic-v2-cpuif-proxy.c
+++ b/arch/arm64/kvm/hyp/vgic-v2-cpuif-proxy.c
@@ -69,14 +69,14 @@ int __hyp_text __vgic_v2_perform_cpuif_access(struct kvm_vcpu *vcpu)
u32 data = vcpu_get_reg(vcpu, rd);
if (__is_be(vcpu)) {
/* guest pre-swabbed data, undo this for writel() */
- data = swab32(data);
+ data = __kvm_swab32(data);
}
writel_relaxed(data, addr);
} else {
u32 data = readl_relaxed(addr);
if (__is_be(vcpu)) {
/* guest expects swabbed data */
- data = swab32(data);
+ data = __kvm_swab32(data);
}
vcpu_set_reg(vcpu, rd, data);
}
--
2.20.1
next prev parent reply other threads:[~2020-02-25 23:52 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-25 23:52 [GIT PULL] KVM/arm fixes for 5.6 Marc Zyngier
2020-02-25 23:52 ` [PATCH 1/5] KVM: arm/arm64: Fix up includes for trace.h Marc Zyngier
2020-02-25 23:52 ` [PATCH 2/5] kvm: arm/arm64: Fold VHE entry/exit work into kvm_vcpu_run_vhe() Marc Zyngier
2020-02-25 23:52 ` [PATCH 3/5] KVM: arm64: Ask the compiler to __always_inline functions used at HYP Marc Zyngier
2020-02-25 23:52 ` Marc Zyngier [this message]
2020-02-25 23:52 ` [PATCH 5/5] arm64: Ask the compiler to __always_inline functions used by KVM " Marc Zyngier
2020-02-28 10:47 ` [GIT PULL] KVM/arm fixes for 5.6 Paolo Bonzini
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