Fix the mismatch between the (incorrect) C signature, C call site, and
asm implementation by aligning all three on an API passing the
parameters (pgd and SP) separately, instead of as a bundled struct.
Remove the now unnecessary memory accesses while the MMU is off from the
asm, which simplifies the C caller (as it does not need to convert a VA
struct pointer to PA) and makes the code slightly more robust by
offsetting the struct fields from C and properly expressing the call to
the C compiler (e.g. type checker and kCFI).
Fixes: f320bc742bc2 ("KVM: arm64: Prepare the creation of s1 mappings at EL2")
Signed-off-by: Pierre-Clément Tosi <ptosi@xxxxxxxxxx>
---
arch/arm64/include/asm/kvm_hyp.h | 4 ++--
arch/arm64/kvm/hyp/nvhe/hyp-init.S | 24 +++++++++++++-----------
arch/arm64/kvm/hyp/nvhe/setup.c | 4 ++--
3 files changed, 17 insertions(+), 15 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_hyp.h b/arch/arm64/include/asm/kvm_hyp.h
index 3e80464f8953..181e10e2575b 100644
--- a/arch/arm64/include/asm/kvm_hyp.h
+++ b/arch/arm64/include/asm/kvm_hyp.h
@@ -123,8 +123,8 @@ void __noreturn __hyp_do_panic(struct kvm_cpu_context *host_ctxt, u64 spsr,
#endif
#ifdef __KVM_NVHE_HYPERVISOR__
-void __pkvm_init_switch_pgd(phys_addr_t phys, unsigned long size,
- phys_addr_t pgd, void *sp, void *cont_fn);
+void __pkvm_init_switch_pgd(phys_addr_t pgd, unsigned long sp,
+ void (*fn)(void));
int __pkvm_init(phys_addr_t phys, unsigned long size, unsigned long nr_cpus,
unsigned long *per_cpu_base, u32 hyp_va_bits);
void __noreturn __host_enter(struct kvm_cpu_context *host_ctxt);
diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-init.S b/arch/arm64/kvm/hyp/nvhe/hyp-init.S
index 2994878d68ea..3a2836a52e85 100644
--- a/arch/arm64/kvm/hyp/nvhe/hyp-init.S
+++ b/arch/arm64/kvm/hyp/nvhe/hyp-init.S
@@ -265,33 +265,35 @@ alternative_else_nop_endif
SYM_CODE_END(__kvm_handle_stub_hvc)
+/*
+ * void __pkvm_init_switch_pgd(phys_addr_t pgd, unsigned long sp,
+ * void (*fn)(void));
+ */
SYM_FUNC_START(__pkvm_init_switch_pgd)
/* Turn the MMU off */
pre_disable_mmu_workaround
- mrs x2, sctlr_el2
- bic x3, x2, #SCTLR_ELx_M
- msr sctlr_el2, x3
+ mrs x3, sctlr_el2
+ bic x4, x3, #SCTLR_ELx_M
+ msr sctlr_el2, x4
isb
tlbi alle2
/* Install the new pgtables */
- ldr x3, [x0, #NVHE_INIT_PGD_PA]
- phys_to_ttbr x4, x3
+ phys_to_ttbr x5, x0
alternative_if ARM64_HAS_CNP
- orr x4, x4, #TTBR_CNP_BIT
+ orr x5, x5, #TTBR_CNP_BIT
alternative_else_nop_endif
- msr ttbr0_el2, x4
+ msr ttbr0_el2, x5
/* Set the new stack pointer */
- ldr x0, [x0, #NVHE_INIT_STACK_HYP_VA]
- mov sp, x0
+ mov sp, x1
/* And turn the MMU back on! */
dsb nsh
isb
- set_sctlr_el2 x2
- ret x1
+ set_sctlr_el2 x3
+ ret x2
SYM_FUNC_END(__pkvm_init_switch_pgd)
.popsection
diff --git a/arch/arm64/kvm/hyp/nvhe/setup.c b/arch/arm64/kvm/hyp/nvhe/setup.c
index 859f22f754d3..598f688b678f 100644
--- a/arch/arm64/kvm/hyp/nvhe/setup.c
+++ b/arch/arm64/kvm/hyp/nvhe/setup.c
@@ -316,7 +316,7 @@ int __pkvm_init(phys_addr_t phys, unsigned long size, unsigned long nr_cpus,
{
struct kvm_nvhe_init_params *params;
void *virt = hyp_phys_to_virt(phys);
- void (*fn)(phys_addr_t params_pa, void *finalize_fn_va);
+ typeof(__pkvm_init_switch_pgd) *fn;
int ret;
BUG_ON(kvm_check_pvm_sysreg_table());
@@ -340,7 +340,7 @@ int __pkvm_init(phys_addr_t phys, unsigned long size, unsigned long nr_cpus,
/* Jump in the idmap page to switch to the new page-tables */
params = this_cpu_ptr(&kvm_init_params);
fn = (typeof(fn))__hyp_pa(__pkvm_init_switch_pgd);
- fn(__hyp_pa(params), __pkvm_init_finalise);
+ fn(params->pgd_pa, params->stack_hyp_va, __pkvm_init_finalise);
unreachable();
}
--
2.45.2.505.gda0bf45e8d-goog
