Commit f11290e0 authored by Fuad Tabba's avatar Fuad Tabba Committed by Marc Zyngier
Browse files

KVM: arm64: Refactor checks for FP state ownership 



To avoid direct comparison against the fp_owner enum, add a new
function that performs the check, host_owns_fp_regs(), to
complement the existing guest_owns_fp_regs().

To check for fpsimd state ownership, use the helpers instead of
directly using the enums.

No functional change intended.

Suggested-by: default avatarMarc Zyngier <maz@kernel.org>
Signed-off-by: default avatarFuad Tabba <tabba@google.com>
Reviewed-by: default avatarMark Brown <broonie@kernel.org>
Acked-by: default avatarOliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20240423150538.2103045-4-tabba@google.com


Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
parent b5b85bd7

arch/arm64/include/asm/kvm_emulate.h

+2 −4
Original line number Diff line number Diff line
@@ -587,16 +587,14 @@ static __always_inline u64 kvm_get_reset_cptr_el2(struct kvm_vcpu *vcpu) 
	} else if (has_hvhe()) {

		val = (CPACR_EL1_FPEN_EL0EN | CPACR_EL1_FPEN_EL1EN);



		if (!vcpu_has_sve(vcpu) ||

		    (*host_data_ptr(fp_owner) != FP_STATE_GUEST_OWNED))

		if (!vcpu_has_sve(vcpu) || !guest_owns_fp_regs())

			val |= CPACR_EL1_ZEN_EL1EN | CPACR_EL1_ZEN_EL0EN;

		if (cpus_have_final_cap(ARM64_SME))

			val |= CPACR_EL1_SMEN_EL1EN | CPACR_EL1_SMEN_EL0EN;

	} else {

		val = CPTR_NVHE_EL2_RES1;



		if (vcpu_has_sve(vcpu) &&

		    (*host_data_ptr(fp_owner) == FP_STATE_GUEST_OWNED))

		if (vcpu_has_sve(vcpu) && guest_owns_fp_regs())

			val |= CPTR_EL2_TZ;

		if (cpus_have_final_cap(ARM64_SME))

			val &= ~CPTR_EL2_TSM;

arch/arm64/include/asm/kvm_host.h

+6 −0
Original line number Diff line number Diff line
@@ -1213,6 +1213,12 @@ static inline bool guest_owns_fp_regs(void) 
	return *host_data_ptr(fp_owner) == FP_STATE_GUEST_OWNED;

}



/* Check whether the FP regs are owned by the host */

static inline bool host_owns_fp_regs(void)

{

	return *host_data_ptr(fp_owner) == FP_STATE_HOST_OWNED;

}



static inline void kvm_init_host_cpu_context(struct kvm_cpu_context *cpu_ctxt)

{

	/* The host's MPIDR is immutable, so let's set it up at boot time */

arch/arm64/kvm/fpsimd.c

+2 −3
Original line number Diff line number Diff line
@@ -141,8 +141,7 @@ void kvm_arch_vcpu_ctxsync_fp(struct kvm_vcpu *vcpu) 


	WARN_ON_ONCE(!irqs_disabled());



	if (*host_data_ptr(fp_owner) == FP_STATE_GUEST_OWNED) {



	if (guest_owns_fp_regs()) {

		/*

		 * Currently we do not support SME guests so SVCR is

		 * always 0 and we just need a variable to point to.
@@ -195,7 +194,7 @@ void kvm_arch_vcpu_put_fp(struct kvm_vcpu *vcpu) 
		isb();

	}



	if (*host_data_ptr(fp_owner) == FP_STATE_GUEST_OWNED) {

	if (guest_owns_fp_regs()) {

		if (vcpu_has_sve(vcpu)) {

			__vcpu_sys_reg(vcpu, ZCR_EL1) = read_sysreg_el1(SYS_ZCR);

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

+1 −1
Original line number Diff line number Diff line
@@ -370,7 +370,7 @@ static bool kvm_hyp_handle_fpsimd(struct kvm_vcpu *vcpu, u64 *exit_code) 
	isb();



	/* Write out the host state if it's in the registers */

	if (*host_data_ptr(fp_owner) == FP_STATE_HOST_OWNED)

	if (host_owns_fp_regs())

		__fpsimd_save_state(*host_data_ptr(fpsimd_state));



	/* Restore the guest state */

arch/arm64/kvm/hyp/nvhe/switch.c

+1 −1
Original line number Diff line number Diff line
@@ -337,7 +337,7 @@ int __kvm_vcpu_run(struct kvm_vcpu *vcpu) 


	__sysreg_restore_state_nvhe(host_ctxt);



	if (*host_data_ptr(fp_owner) == FP_STATE_GUEST_OWNED)

	if (guest_owns_fp_regs())

		__fpsimd_save_fpexc32(vcpu);



	__debug_switch_to_host(vcpu);