[PATCH v3 19/32] KVM: arm64: Set host stage 2 using kvm_nvhe_init_params

Quentin Perret
2021-03-03T14:25:06Z

Move the registers relevant to host stage 2 enablement to
kvm_nvhe_init_params to prepare the ground for enabling it in later
patches.

Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Quentin Perret <qperret@google.com>
---
arch/arm64/include/asm/kvm_asm.h | 3 +++
arch/arm64/kernel/asm-offsets.c | 3 +++
arch/arm64/kvm/arm.c | 5 +++++
arch/arm64/kvm/hyp/nvhe/hyp-init.S | 14 +++++++++-----
arch/arm64/kvm/hyp/nvhe/switch.c | 5 +----
5 files changed, 21 insertions(+), 9 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h
index db20a9477870..6dce860f8bca 100644
--- a/arch/arm64/include/asm/kvm_asm.h
+++ b/arch/arm64/include/asm/kvm_asm.h
@@ -158,6 +158,9 @@ struct kvm_nvhe_init_params {
unsigned long tpidr_el2;
unsigned long stack_hyp_va;
phys_addr_t pgd_pa;
+ unsigned long hcr_el2;
+ unsigned long vttbr;
+ unsigned long vtcr;
};

/* Translate a kernel address @ptr into its equivalent linear mapping */
diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c
index a36e2fc330d4..8930b42f6418 100644
--- a/arch/arm64/kernel/asm-offsets.c
+++ b/arch/arm64/kernel/asm-offsets.c
@@ -120,6 +120,9 @@ int main(void)
DEFINE(NVHE_INIT_TPIDR_EL2, offsetof(struct kvm_nvhe_init_params, tpidr_el2));
DEFINE(NVHE_INIT_STACK_HYP_VA, offsetof(struct kvm_nvhe_init_params, stack_hyp_va));
DEFINE(NVHE_INIT_PGD_PA, offsetof(struct kvm_nvhe_init_params, pgd_pa));
+ DEFINE(NVHE_INIT_HCR_EL2, offsetof(struct kvm_nvhe_init_params, hcr_el2));
+ DEFINE(NVHE_INIT_VTTBR, offsetof(struct kvm_nvhe_init_params, vttbr));
+ DEFINE(NVHE_INIT_VTCR, offsetof(struct kvm_nvhe_init_params, vtcr));
#endif
#ifdef CONFIG_CPU_PM
DEFINE(CPU_CTX_SP, offsetof(struct cpu_suspend_ctx, sp));
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 5a97abdc3ba6..b6a818f88051 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -1413,6 +1413,11 @@ static void cpu_prepare_hyp_mode(int cpu)

params->stack_hyp_va = kern_hyp_va(per_cpu(kvm_arm_hyp_stack_page, cpu) + PAGE_SIZE);
params->pgd_pa = kvm_mmu_get_httbr();
+ if (is_protected_kvm_enabled())
+ params->hcr_el2 = HCR_HOST_NVHE_PROTECTED_FLAGS;
+ else
+ params->hcr_el2 = HCR_HOST_NVHE_FLAGS;
+ params->vttbr = params->vtcr = 0;

/*
* Flush the init params from the data cache because the struct will
diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-init.S b/arch/arm64/kvm/hyp/nvhe/hyp-init.S
index bc56ea92b812..f312672d895e 100644
--- a/arch/arm64/kvm/hyp/nvhe/hyp-init.S
+++ b/arch/arm64/kvm/hyp/nvhe/hyp-init.S
@@ -83,11 +83,6 @@ SYM_CODE_END(__kvm_hyp_init)
* x0: struct kvm_nvhe_init_params PA
*/
SYM_CODE_START_LOCAL(___kvm_hyp_init)
-alternative_if ARM64_KVM_PROTECTED_MODE
- mov_q x1, HCR_HOST_NVHE_PROTECTED_FLAGS
- msr hcr_el2, x1
-alternative_else_nop_endif
-
ldr x1, [x0, #NVHE_INIT_TPIDR_EL2]
msr tpidr_el2, x1

@@ -97,6 +92,15 @@ alternative_else_nop_endif
ldr x1, [x0, #NVHE_INIT_MAIR_EL2]
msr mair_el2, x1

+ ldr x1, [x0, #NVHE_INIT_HCR_EL2]
+ msr hcr_el2, x1
+
+ ldr x1, [x0, #NVHE_INIT_VTTBR]
+ msr vttbr_el2, x1
+
+ ldr x1, [x0, #NVHE_INIT_VTCR]
+ msr vtcr_el2, x1
+
ldr x1, [x0, #NVHE_INIT_PGD_PA]
phys_to_ttbr x2, x1
alternative_if ARM64_HAS_CNP
diff --git a/arch/arm64/kvm/hyp/nvhe/switch.c b/arch/arm64/kvm/hyp/nvhe/switch.c
index f3d0e9eca56c..979a76cdf9fb 100644
--- a/arch/arm64/kvm/hyp/nvhe/switch.c
+++ b/arch/arm64/kvm/hyp/nvhe/switch.c
@@ -97,10 +97,7 @@ static void __deactivate_traps(struct kvm_vcpu *vcpu)
mdcr_el2 |= MDCR_EL2_E2PB_MASK << MDCR_EL2_E2PB_SHIFT;

write_sysreg(mdcr_el2, mdcr_el2);
- if (is_protected_kvm_enabled())
- write_sysreg(HCR_HOST_NVHE_PROTECTED_FLAGS, hcr_el2);
- else
- write_sysreg(HCR_HOST_NVHE_FLAGS, hcr_el2);
+ write_sysreg(this_cpu_ptr(&kvm_init_params)->hcr_el2, hcr_el2);
write_sysreg(CPTR_EL2_DEFAULT, cptr_el2);
write_sysreg(__kvm_hyp_host_vector, vbar_el2);
}