Commit af9a0e21 authored by Marc Zyngier's avatar Marc Zyngier
Browse files

KVM: arm64: Introduce flag shadowing TIF_FOREIGN_FPSTATE 



We currently have to maintain a mapping the thread_info structure
at EL2 in order to be able to check the TIF_FOREIGN_FPSTATE flag.

In order to eventually get rid of this, start with a vcpu flag that
shadows the thread flag on each entry into the hypervisor.

Reviewed-by: default avatarMark Brown <broonie@kernel.org>
Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
parent e66425fc

arch/arm64/include/asm/kvm_host.h

+2 −0
Original line number Diff line number Diff line
@@ -441,6 +441,7 @@ struct kvm_vcpu_arch { 


#define KVM_ARM64_DEBUG_STATE_SAVE_SPE	(1 << 12) /* Save SPE context if active  */

#define KVM_ARM64_DEBUG_STATE_SAVE_TRBE	(1 << 13) /* Save TRBE context if active  */

#define KVM_ARM64_FP_FOREIGN_FPSTATE	(1 << 14)



#define KVM_GUESTDBG_VALID_MASK (KVM_GUESTDBG_ENABLE | \

				 KVM_GUESTDBG_USE_SW_BP | \
@@ -736,6 +737,7 @@ long kvm_vm_ioctl_mte_copy_tags(struct kvm *kvm, 
/* Guest/host FPSIMD coordination helpers */

int kvm_arch_vcpu_run_map_fp(struct kvm_vcpu *vcpu);

void kvm_arch_vcpu_load_fp(struct kvm_vcpu *vcpu);

void kvm_arch_vcpu_ctxflush_fp(struct kvm_vcpu *vcpu);

void kvm_arch_vcpu_ctxsync_fp(struct kvm_vcpu *vcpu);

void kvm_arch_vcpu_put_fp(struct kvm_vcpu *vcpu);

arch/arm64/kvm/arm.c

+1 −0
Original line number Diff line number Diff line
@@ -849,6 +849,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu) 
		}



		kvm_arm_setup_debug(vcpu);

		kvm_arch_vcpu_ctxflush_fp(vcpu);



		/**************************************************************

		 * Enter the guest

arch/arm64/kvm/fpsimd.c

+8 −0
Original line number Diff line number Diff line
@@ -79,6 +79,14 @@ void kvm_arch_vcpu_load_fp(struct kvm_vcpu *vcpu) 
		vcpu->arch.flags |= KVM_ARM64_HOST_SVE_ENABLED;

}



void kvm_arch_vcpu_ctxflush_fp(struct kvm_vcpu *vcpu)

{

	if (test_thread_flag(TIF_FOREIGN_FPSTATE))

		vcpu->arch.flags |= KVM_ARM64_FP_FOREIGN_FPSTATE;

	else

		vcpu->arch.flags &= ~KVM_ARM64_FP_FOREIGN_FPSTATE;

}



/*

 * If the guest FPSIMD state was loaded, update the host's context

 * tracking data mark the CPU FPSIMD regs as dirty and belonging to vcpu

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

+1 −1
Original line number Diff line number Diff line
@@ -49,7 +49,7 @@ static inline bool update_fp_enabled(struct kvm_vcpu *vcpu) 
	 * trap the accesses.

	 */

	if (!system_supports_fpsimd() ||

	    vcpu->arch.host_thread_info->flags & _TIF_FOREIGN_FPSTATE)

	    vcpu->arch.flags & KVM_ARM64_FP_FOREIGN_FPSTATE)

		vcpu->arch.flags &= ~(KVM_ARM64_FP_ENABLED |

				      KVM_ARM64_FP_HOST);