[PATCH v7 15/23] arm64: Honor VHE being disabled from the command-line

Marc Zyngier
2021-02-08T10:23:19Z

Finally we can check whether VHE is disabled on the command line,
and not enable it if that's the user's wish.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: David Brazdil <dbrazdil@google.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
---
arch/arm64/kernel/asm-offsets.c | 3 +++
arch/arm64/kernel/hyp-stub.S | 11 +++++++++++
2 files changed, 14 insertions(+)

diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c
index f42fd9e33981..1add0f21bffe 100644
--- a/arch/arm64/kernel/asm-offsets.c
+++ b/arch/arm64/kernel/asm-offsets.c
@@ -99,6 +99,9 @@ int main(void)
DEFINE(CPU_BOOT_STACK, offsetof(struct secondary_data, stack));
DEFINE(CPU_BOOT_TASK, offsetof(struct secondary_data, task));
BLANK();
+ DEFINE(FTR_OVR_VAL_OFFSET, offsetof(struct arm64_ftr_override, val));
+ DEFINE(FTR_OVR_MASK_OFFSET, offsetof(struct arm64_ftr_override, mask));
+ BLANK();
#ifdef CONFIG_KVM
DEFINE(VCPU_CONTEXT, offsetof(struct kvm_vcpu, arch.ctxt));
DEFINE(VCPU_FAULT_DISR, offsetof(struct kvm_vcpu, arch.fault.disr_el1));
diff --git a/arch/arm64/kernel/hyp-stub.S b/arch/arm64/kernel/hyp-stub.S
index 6229315d533d..3e08dcc924b5 100644
--- a/arch/arm64/kernel/hyp-stub.S
+++ b/arch/arm64/kernel/hyp-stub.S
@@ -87,6 +87,17 @@ SYM_CODE_START_LOCAL(mutate_to_vhe)
ubfx x1, x1, #ID_AA64MMFR1_VHE_SHIFT, #4
cbz x1, 1f

+ // Check whether VHE is disabled from the command line
+ adr_l x1, id_aa64mmfr1_override
+ ldr x2, [x1, FTR_OVR_VAL_OFFSET]
+ ldr x1, [x1, FTR_OVR_MASK_OFFSET]
+ ubfx x2, x2, #ID_AA64MMFR1_VHE_SHIFT, #4
+ ubfx x1, x1, #ID_AA64MMFR1_VHE_SHIFT, #4
+ cmp x1, xzr
+ and x2, x2, x1
+ csinv x2, x2, xzr, ne
+ cbz x2, 1f
+
// Engage the VHE magic!
mov_q x0, HCR_HOST_VHE_FLAGS
msr hcr_el2, x0
--
2.29.2