[PATCH v3 09/17] KVM: arm64: Key use of VHE instructions in nVHE code off ARM64_KVM_HVHE

Marc Zyngier
2023-06-09T16:22:26Z

We can now start with the fun stuff: if we enable VHE *only* for
the hypervisor, we need to generate the VHE instructions when
accessing the system registers.

For this, reporpose the alternative sequence to be keyed off
ARM64_KVM_HVHE in the nVHE hypervisor code, and only there.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
arch/arm64/include/asm/kvm_hyp.h | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_hyp.h b/arch/arm64/include/asm/kvm_hyp.h
index fea04eb25cb4..b7238c72a04c 100644
--- a/arch/arm64/include/asm/kvm_hyp.h
+++ b/arch/arm64/include/asm/kvm_hyp.h
@@ -33,12 +33,18 @@ DECLARE_PER_CPU(struct kvm_nvhe_init_params, kvm_init_params);

#else // !__KVM_VHE_HYPERVISOR__

+#if defined(__KVM_NVHE_HYPERVISOR__)
+#define VHE_ALT_KEY ARM64_KVM_HVHE
+#else
+#define VHE_ALT_KEY ARM64_HAS_VIRT_HOST_EXTN
+#endif
+
#define read_sysreg_elx(r,nvh,vh) \
({ \
u64 reg; \
- asm volatile(ALTERNATIVE(__mrs_s("%0", r##nvh), \
+ asm volatile(ALTERNATIVE(__mrs_s("%0", r##nvh), \
__mrs_s("%0", r##vh), \
- ARM64_HAS_VIRT_HOST_EXTN) \
+ VHE_ALT_KEY) \
: "=r" (reg)); \
reg; \
})
@@ -48,7 +54,7 @@ DECLARE_PER_CPU(struct kvm_nvhe_init_params, kvm_init_params);
u64 __val = (u64)(v); \
asm volatile(ALTERNATIVE(__msr_s(r##nvh, "%x0"), \
__msr_s(r##vh, "%x0"), \
- ARM64_HAS_VIRT_HOST_EXTN) \
+ VHE_ALT_KEY) \
: : "rZ" (__val)); \
} while (0)

--
2.34.1