ANDROID: KVM: arm64: Allow tweaking HCR_EL2 from modules pKVM modules may need to enable additional traps on top of what pKVM already enables. To allow this use-case, expose a function allowing to manipulate HCR_EL2 on the current CPU. This configuration will be persistent across power management cycles and such as it is propagated all the way to the init params per-cpu struct. Bug: 458241298 Signed-off-by: Quentin Perret <qperret@google.com> Signed-off-by: Fuad Tabba <tabba@google.com> Change-Id: I21d596bd1d01f4edc48a188cc3c2eb78dc9a4444 (cherry picked from commit 69365c8419b4d206b862c05c008ba61336d36fdc)
diff --git a/arch/arm64/include/asm/kvm_pkvm_module.h b/arch/arm64/include/asm/kvm_pkvm_module.h index c404d7a..826279c 100644 --- a/arch/arm64/include/asm/kvm_pkvm_module.h +++ b/arch/arm64/include/asm/kvm_pkvm_module.h
@@ -28,6 +28,7 @@ struct pkvm_module_ops { void *(*linear_map_early)(phys_addr_t phys, size_t size, enum kvm_pgtable_prot prot); void (*linear_unmap_early)(void *addr, size_t size); void (*flush_dcache_to_poc)(void *addr, size_t size); + void (*update_hcr_el2)(unsigned long set_mask, unsigned long clear_mask); int (*register_host_perm_fault_handler)(int (*cb)(struct user_pt_regs *regs, u64 esr, u64 addr)); int (*register_host_smc_handler)(bool (*cb)(struct user_pt_regs *)); int (*register_default_trap_handler)(bool (*cb)(struct user_pt_regs *));
diff --git a/arch/arm64/kvm/hyp/nvhe/modules.c b/arch/arm64/kvm/hyp/nvhe/modules.c index e2f4e0e..d7b6d63 100644 --- a/arch/arm64/kvm/hyp/nvhe/modules.c +++ b/arch/arm64/kvm/hyp/nvhe/modules.c
@@ -35,6 +35,16 @@ bool pkvm_modules_enabled(void) return __pkvm_modules_enabled; } +static void __update_hcr_el2(unsigned long set_mask, unsigned long clear_mask) +{ + struct kvm_nvhe_init_params *params = this_cpu_ptr(&kvm_init_params); + + params->hcr_el2 |= set_mask; + params->hcr_el2 &= ~clear_mask; + __kvm_flush_dcache_to_poc(params, sizeof(*params)); + write_sysreg(params->hcr_el2, hcr_el2); +} + static atomic_t early_lm_pages; static void *__pkvm_linear_map_early(phys_addr_t phys, size_t size, enum kvm_pgtable_prot prot) { @@ -101,6 +111,7 @@ const struct pkvm_module_ops module_ops = { .linear_map_early = __pkvm_linear_map_early, .linear_unmap_early = __pkvm_linear_unmap_early, .flush_dcache_to_poc = __kvm_flush_dcache_to_poc, + .update_hcr_el2 = __update_hcr_el2, .register_host_perm_fault_handler = hyp_register_host_perm_fault_handler, .register_host_smc_handler = __pkvm_register_host_smc_handler, .register_default_trap_handler = __pkvm_register_default_trap_handler,