ANDROID: KVM: arm64: Allow tweaking HFGWTR_EL2 from modules

pKVM modules may need to enable fine grain traps. To allow this
use-case, expose a function allowing to manipulate HFGWTR_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: 245034629
Change-Id: If9c29849df50847d3a796345927bd51c37c358bc
Signed-off-by: Quentin Perret <qperret@google.com>
This commit is contained in:
Quentin Perret 2023-02-03 14:18:57 +00:00 committed by Carlos Llamas
parent 47dfb4dc1f
commit 444b34b83a
5 changed files with 17 additions and 0 deletions

View file

@ -221,6 +221,7 @@ struct kvm_nvhe_init_params {
unsigned long stack_pa;
phys_addr_t pgd_pa;
unsigned long hcr_el2;
unsigned long hfgwtr_el2;
unsigned long vttbr;
unsigned long vtcr;
};

View file

@ -31,6 +31,7 @@ struct pkvm_module_ops {
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);
void (*update_hfgwtr_el2)(unsigned long set_mask, unsigned long clear_mask);
int (*register_host_perm_fault_handler)(int (*cb)(struct kvm_cpu_context *ctxt, u64 esr, u64 addr));
int (*host_stage2_mod_prot)(u64 pfn, enum kvm_pgtable_prot prot);
int (*host_stage2_get_leaf)(phys_addr_t phys, kvm_pte_t *ptep, u32 *level);

View file

@ -128,6 +128,7 @@ int main(void)
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_HFGWTR_EL2, offsetof(struct kvm_nvhe_init_params, hfgwtr_el2));
DEFINE(NVHE_INIT_VTTBR, offsetof(struct kvm_nvhe_init_params, vttbr));
DEFINE(NVHE_INIT_VTCR, offsetof(struct kvm_nvhe_init_params, vtcr));
#endif

View file

@ -95,6 +95,9 @@ SYM_CODE_START_LOCAL(___kvm_hyp_init)
ldr x1, [x0, #NVHE_INIT_HCR_EL2]
msr hcr_el2, x1
ldr x1, [x0, #NVHE_INIT_HFGWTR_EL2]
msr_s SYS_HFGWTR_EL2, x1
ldr x1, [x0, #NVHE_INIT_VTTBR]
msr vttbr_el2, x1

View file

@ -27,6 +27,16 @@ static void __update_hcr_el2(unsigned long set_mask, unsigned long clear_mask)
write_sysreg(params->hcr_el2, hcr_el2);
}
static void __update_hfgwtr_el2(unsigned long set_mask, unsigned long clear_mask)
{
struct kvm_nvhe_init_params *params = this_cpu_ptr(&kvm_init_params);
params->hfgwtr_el2 |= set_mask;
params->hfgwtr_el2 &= ~clear_mask;
__kvm_flush_dcache_to_poc(params, sizeof(*params));
write_sysreg_s(params->hfgwtr_el2, SYS_HFGWTR_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)
{
@ -89,6 +99,7 @@ const struct pkvm_module_ops module_ops = {
.linear_unmap_early = __pkvm_linear_unmap_early,
.flush_dcache_to_poc = __kvm_flush_dcache_to_poc,
.update_hcr_el2 = __update_hcr_el2,
.update_hfgwtr_el2 = __update_hfgwtr_el2,
.register_host_perm_fault_handler = hyp_register_host_perm_fault_handler,
.host_stage2_mod_prot = module_change_host_page_prot,
.host_stage2_get_leaf = host_stage2_get_leaf,