diff mbox series

[RFC,v2,04/26] KVM: arm64: Initialize kvm_nvhe_init_params early

Message ID 20210108121524.656872-5-qperret@google.com (mailing list archive)
State New, archived
Headers show
Series KVM/arm64: A stage 2 for the host | expand

Commit Message

Quentin Perret Jan. 8, 2021, 12:15 p.m. UTC 
Move the initialization of kvm_nvhe_init_params in a dedicated function
that is run early, and only once during KVM init, rather than every time
the KVM vectors are set and reset.

This also opens the opportunity for the hypervisor to change the init
structs during boot, hence simplifying the replacement of host-provided
page-tables and stacks by the ones the hypervisor will create for
itself.

Signed-off-by: Quentin Perret <qperret@google.com>
---
 arch/arm64/kvm/arm.c | 28 ++++++++++++++++++++--------
 1 file changed, 20 insertions(+), 8 deletions(-)

Comments

Will Deacon Feb. 1, 2021, 5:41 p.m. UTC | #1 
On Fri, Jan 08, 2021 at 12:15:02PM +0000, Quentin Perret wrote:
> Move the initialization of kvm_nvhe_init_params in a dedicated function
> that is run early, and only once during KVM init, rather than every time
> the KVM vectors are set and reset.
> 
> This also opens the opportunity for the hypervisor to change the init
> structs during boot, hence simplifying the replacement of host-provided
> page-tables and stacks by the ones the hypervisor will create for
> itself.
> 
> Signed-off-by: Quentin Perret <qperret@google.com>
> ---
>  arch/arm64/kvm/arm.c | 28 ++++++++++++++++++++--------
>  1 file changed, 20 insertions(+), 8 deletions(-)
> 
> diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
> index 04c44853b103..3ac0f3425833 100644
> --- a/arch/arm64/kvm/arm.c
> +++ b/arch/arm64/kvm/arm.c

[...]

> @@ -1807,6 +1813,12 @@ static int init_hyp_mode(void)
>  			goto out_err;
>  	}
>  
> +	/*
> +	 * Prepare the CPU initialization parameters
> +	 */
> +	for_each_possible_cpu(cpu)
> +		cpu_prepare_hyp_mode(cpu);
> +

This is the fifth for_each_possible_cpu() loop in this function; can any of
them be merged together?

Will
diff mbox series

Patch

diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 04c44853b103..3ac0f3425833 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -1383,21 +1383,17 @@  static int kvm_init_vector_slots(void)
 	return 0;
 }
 
-static void cpu_init_hyp_mode(void)
+static void cpu_prepare_hyp_mode(int cpu)
 {
-	struct kvm_nvhe_init_params *params = this_cpu_ptr_nvhe_sym(kvm_init_params);
-	struct arm_smccc_res res;
+	struct kvm_nvhe_init_params *params = per_cpu_ptr_nvhe_sym(kvm_init_params, cpu);
 	unsigned long tcr;
 
-	/* Switch from the HYP stub to our own HYP init vector */
-	__hyp_set_vectors(kvm_get_idmap_vector());
-
 	/*
 	 * Calculate the raw per-cpu offset without a translation from the
 	 * 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.
 	 */
-	params->tpidr_el2 = (unsigned long)this_cpu_ptr_nvhe_sym(__per_cpu_start) -
+	params->tpidr_el2 = (unsigned long)per_cpu_ptr_nvhe_sym(__per_cpu_start, cpu) -
 			    (unsigned long)kvm_ksym_ref(CHOOSE_NVHE_SYM(__per_cpu_start));
 
 	params->mair_el2 = read_sysreg(mair_el1);
@@ -1421,7 +1417,7 @@  static void cpu_init_hyp_mode(void)
 	tcr |= (idmap_t0sz & GENMASK(TCR_TxSZ_WIDTH - 1, 0)) << TCR_T0SZ_OFFSET;
 	params->tcr_el2 = tcr;
 
-	params->stack_hyp_va = kern_hyp_va(__this_cpu_read(kvm_arm_hyp_stack_page) + PAGE_SIZE);
+	params->stack_hyp_va = kern_hyp_va(per_cpu(kvm_arm_hyp_stack_page, cpu) + PAGE_SIZE);
 	params->pgd_pa = kvm_mmu_get_httbr();
 
 	/*
@@ -1429,6 +1425,15 @@  static void cpu_init_hyp_mode(void)
 	 * be read while the MMU is off.
 	 */
 	kvm_flush_dcache_to_poc(params, sizeof(*params));
+}
+
+static void cpu_init_hyp_mode(void)
+{
+	struct kvm_nvhe_init_params *params;
+	struct arm_smccc_res res;
+
+	/* Switch from the HYP stub to our own HYP init vector */
+	__hyp_set_vectors(kvm_get_idmap_vector());
 
 	/*
 	 * Call initialization code, and switch to the full blown HYP code.
@@ -1437,6 +1442,7 @@  static void cpu_init_hyp_mode(void)
 	 * cpus_have_const_cap() wrapper.
 	 */
 	BUG_ON(!system_capabilities_finalized());
+	params = this_cpu_ptr_nvhe_sym(kvm_init_params);
 	arm_smccc_1_1_hvc(KVM_HOST_SMCCC_FUNC(__kvm_hyp_init), virt_to_phys(params), &res);
 	WARN_ON(res.a0 != SMCCC_RET_SUCCESS);
 
@@ -1807,6 +1813,12 @@  static int init_hyp_mode(void)
 			goto out_err;
 	}
 
+	/*
+	 * Prepare the CPU initialization parameters
+	 */
+	for_each_possible_cpu(cpu)
+		cpu_prepare_hyp_mode(cpu);
+
 	return 0;
 
 out_err: