Commit b619d9aa authored by Andrew Scull's avatar Andrew Scull Committed by Marc Zyngier
Browse files

KVM: arm64: Introduce hyp context 



During __guest_enter, save and restore from a new hyp context rather
than the host context. This is preparation for separation of the hyp and
host context in nVHE.

Signed-off-by: default avatarAndrew Scull <ascull@google.com>
Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200915104643.2543892-9-ascull@google.com
parent 472fc011

arch/arm64/include/asm/kvm_hyp.h

+2 −1
Original line number Diff line number Diff line
@@ -12,6 +12,7 @@ 
#include <asm/alternative.h>

#include <asm/sysreg.h>



DECLARE_PER_CPU(struct kvm_cpu_context, kvm_hyp_ctxt);

DECLARE_PER_CPU(unsigned long, kvm_hyp_vector);



#define read_sysreg_elx(r,nvh,vh)					\
@@ -89,7 +90,7 @@ void activate_traps_vhe_load(struct kvm_vcpu *vcpu); 
void deactivate_traps_vhe_put(void);

#endif



u64 __guest_enter(struct kvm_vcpu *vcpu, struct kvm_cpu_context *host_ctxt);

u64 __guest_enter(struct kvm_vcpu *vcpu);



void __noreturn hyp_panic(void);

#ifdef __KVM_NVHE_HYPERVISOR__

arch/arm64/kernel/image-vars.h

+1 −0
Original line number Diff line number Diff line
@@ -71,6 +71,7 @@ KVM_NVHE_ALIAS(kvm_update_va_mask); 
/* Global kernel state accessed by nVHE hyp code. */

KVM_NVHE_ALIAS(arm64_ssbd_callback_required);

KVM_NVHE_ALIAS(kvm_host_data);

KVM_NVHE_ALIAS(kvm_hyp_ctxt);

KVM_NVHE_ALIAS(kvm_hyp_vector);

KVM_NVHE_ALIAS(kvm_vgic_global_state);

arch/arm64/kvm/arm.c

+10 −0
Original line number Diff line number Diff line
@@ -47,6 +47,7 @@ __asm__(".arch_extension virt"); 
#endif



DEFINE_PER_CPU(struct kvm_host_data, kvm_host_data);

DEFINE_PER_CPU(struct kvm_cpu_context, kvm_hyp_ctxt);

DEFINE_PER_CPU(unsigned long, kvm_hyp_vector);

static DEFINE_PER_CPU(unsigned long, kvm_arm_hyp_stack_page);
@@ -1542,6 +1543,7 @@ static int init_hyp_mode(void) 


	for_each_possible_cpu(cpu) {

		struct kvm_host_data *cpu_data;

		struct kvm_cpu_context *hyp_ctxt;

		unsigned long *vector;



		cpu_data = per_cpu_ptr(&kvm_host_data, cpu);
@@ -1552,6 +1554,14 @@ static int init_hyp_mode(void) 
			goto out_err;

		}



		hyp_ctxt = per_cpu_ptr(&kvm_hyp_ctxt, cpu);

		err = create_hyp_mappings(hyp_ctxt, hyp_ctxt + 1, PAGE_HYP);



		if (err) {

			kvm_err("Cannot map hyp context: %d\n", err);

			goto out_err;

		}



		vector = per_cpu_ptr(&kvm_hyp_vector, cpu);

		err = create_hyp_mappings(vector, vector + 1, PAGE_HYP);

arch/arm64/kvm/hyp/entry.S

+5 −5
Original line number Diff line number Diff line
@@ -57,15 +57,15 @@ 
.endm



/*

 * u64 __guest_enter(struct kvm_vcpu *vcpu,

 *		     struct kvm_cpu_context *host_ctxt);

 * u64 __guest_enter(struct kvm_vcpu *vcpu);

 */

SYM_FUNC_START(__guest_enter)

	// x0: vcpu

	// x1: host context

	// x2-x17: clobbered by macros

	// x1-x17: clobbered by macros

	// x29: guest context



	hyp_adr_this_cpu x1, kvm_hyp_ctxt, x2



	// Store the host regs

	save_callee_saved_regs x1
@@ -148,7 +148,7 @@ SYM_INNER_LABEL(__guest_exit, SYM_L_GLOBAL) 
	// Store the guest's sp_el0

	save_sp_el0	x1, x2



	get_host_ctxt	x2, x3

	hyp_adr_this_cpu x2, kvm_hyp_ctxt, x3



	// Macro ptrauth_switch_to_guest format:

	// 	ptrauth_switch_to_host(guest cxt, host cxt, tmp1, tmp2, tmp3)

arch/arm64/kvm/hyp/include/hyp/switch.h

+1 −1
Original line number Diff line number Diff line
@@ -381,7 +381,7 @@ static inline bool __hyp_handle_ptrauth(struct kvm_vcpu *vcpu) 
	    !esr_is_ptrauth_trap(kvm_vcpu_get_esr(vcpu)))

		return false;



	ctxt = &__hyp_this_cpu_ptr(kvm_host_data)->host_ctxt;

	ctxt = __hyp_this_cpu_ptr(kvm_hyp_ctxt);

	__ptrauth_save_key(ctxt, APIA);

	__ptrauth_save_key(ctxt, APIB);

	__ptrauth_save_key(ctxt, APDA);

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