From 63fec24351e827021137a15b307bd1e64772b7fe Mon Sep 17 00:00:00 2001 From: David Brazdil Date: Wed, 2 Dec 2020 18:41:06 +0000 Subject: 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 Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20201202184122.26046-11-dbrazdil@google.com --- arch/arm64/kvm/arm.c | 23 +++++++++++++---------- arch/arm64/kvm/hyp/nvhe/hyp-init.S | 16 +++++++--------- arch/arm64/kvm/hyp/nvhe/hyp-main.c | 2 ++ 3 files changed, 22 insertions(+), 19 deletions(-) (limited to 'arch/arm64/kvm') diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 1f86d7d0ecf2..0b823e448917 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); /* diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-init.S b/arch/arm64/kvm/hyp/nvhe/hyp-init.S index 931a8c38f085..e712e317337c 100644 --- a/arch/arm64/kvm/hyp/nvhe/hyp-init.S +++ b/arch/arm64/kvm/hyp/nvhe/hyp-init.S @@ -47,9 +47,7 @@ __invalid: /* * x0: SMCCC function ID - * x1: HYP pgd - * x2: per-CPU offset - * x3: HYP stack + * x1: struct kvm_nvhe_init_params PA */ __do_hyp_init: /* Check for a stub HVC call */ @@ -70,10 +68,13 @@ __do_hyp_init: mov x0, #SMCCC_RET_NOT_SUPPORTED eret -1: - /* Set tpidr_el2 for use by HYP to free a register */ - msr tpidr_el2, x2 +1: ldr x0, [x1, #NVHE_INIT_TPIDR_EL2] + msr tpidr_el2, x0 + ldr x0, [x1, #NVHE_INIT_STACK_HYP_VA] + mov sp, x0 + + ldr x1, [x1, #NVHE_INIT_PGD_PA] phys_to_ttbr x0, x1 alternative_if ARM64_HAS_CNP orr x0, x0, #TTBR_CNP_BIT @@ -133,9 +134,6 @@ alternative_else_nop_endif msr sctlr_el2, x0 isb - /* Set the stack */ - mov sp, x3 - /* Set the host vector */ ldr x0, =__kvm_hyp_host_vector kimg_hyp_va x0, x1 diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c index 82df7fc24760..a4f1cac714d7 100644 --- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c +++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c @@ -16,6 +16,8 @@ #define DECLARE_REG(type, name, ctxt, reg) \ type name = (type)cpu_reg(ctxt, (reg)) +DEFINE_PER_CPU(struct kvm_nvhe_init_params, kvm_init_params); + static void handle___kvm_vcpu_run(struct kvm_cpu_context *host_ctxt) { DECLARE_REG(struct kvm_vcpu *, vcpu, host_ctxt, 1); -- cgit v1.2.3