KVM: arm64: Move hyp-init params to a per-CPU struct
Once we start initializing KVM on newly booted cores before the rest of
the kernel, parameters to __do_hyp_init will need to be provided by EL2
rather than EL1. At that point it will not be possible to pass its three
arguments directly because PSCI_CPU_ON only supports one context
argument.
Refactor __do_hyp_init to accept its parameters in a struct. This
prepares the code for KVM booting cores as well as removes any limits on
the number of __do_hyp_init arguments.
Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201202184122.26046-11-dbrazdil@google.com
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 1f86d7d0..0b823e4 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -52,6 +52,7 @@ DECLARE_KVM_HYP_PER_CPU(unsigned long, kvm_hyp_vector);
static DEFINE_PER_CPU(unsigned long, kvm_arm_hyp_stack_page);
unsigned long kvm_arm_hyp_percpu_base[NR_CPUS];
+DECLARE_KVM_NVHE_PER_CPU(struct kvm_nvhe_init_params, kvm_init_params);
/* The VMID used in the VTTBR */
static atomic64_t kvm_vmid_gen = ATOMIC64_INIT(1);
@@ -1333,9 +1334,7 @@ static int kvm_map_vectors(void)
static void cpu_init_hyp_mode(void)
{
- phys_addr_t pgd_ptr;
- unsigned long hyp_stack_ptr;
- unsigned long tpidr_el2;
+ struct kvm_nvhe_init_params *params = this_cpu_ptr_nvhe_sym(kvm_init_params);
struct arm_smccc_res res;
/* Switch from the HYP stub to our own HYP init vector */
@@ -1346,12 +1345,17 @@ static void cpu_init_hyp_mode(void)
* kernel's mapping to the linear mapping, and store it in tpidr_el2
* so that we can use adr_l to access per-cpu variables in EL2.
*/
- tpidr_el2 = (unsigned long)this_cpu_ptr_nvhe_sym(__per_cpu_start) -
- (unsigned long)kvm_ksym_ref(CHOOSE_NVHE_SYM(__per_cpu_start));
+ params->tpidr_el2 = (unsigned long)this_cpu_ptr_nvhe_sym(__per_cpu_start) -
+ (unsigned long)kvm_ksym_ref(CHOOSE_NVHE_SYM(__per_cpu_start));
- pgd_ptr = kvm_mmu_get_httbr();
- hyp_stack_ptr = __this_cpu_read(kvm_arm_hyp_stack_page) + PAGE_SIZE;
- hyp_stack_ptr = kern_hyp_va(hyp_stack_ptr);
+ params->stack_hyp_va = kern_hyp_va(__this_cpu_read(kvm_arm_hyp_stack_page) + PAGE_SIZE);
+ params->pgd_pa = kvm_mmu_get_httbr();
+
+ /*
+ * Flush the init params from the data cache because the struct will
+ * be read while the MMU is off.
+ */
+ kvm_flush_dcache_to_poc(params, sizeof(*params));
/*
* Call initialization code, and switch to the full blown HYP code.
@@ -1360,8 +1364,7 @@ static void cpu_init_hyp_mode(void)
* cpus_have_const_cap() wrapper.
*/
BUG_ON(!system_capabilities_finalized());
- arm_smccc_1_1_hvc(KVM_HOST_SMCCC_FUNC(__kvm_hyp_init),
- pgd_ptr, tpidr_el2, hyp_stack_ptr, &res);
+ arm_smccc_1_1_hvc(KVM_HOST_SMCCC_FUNC(__kvm_hyp_init), virt_to_phys(params), &res);
WARN_ON(res.a0 != SMCCC_RET_SUCCESS);
/*