Commit 72c62700 authored by Marc Zyngier's avatar Marc Zyngier Committed by Oliver Upton
Browse files

KVM: arm64: Condition FGT registers on feature availability 



We shouldn't expose the FEAT_FGT registers unconditionally. Make
them dependent on FEAT_FGT being actually advertised to the guest.

Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20250714122634.3334816-8-maz@kernel.org


Signed-off-by: default avatarOliver Upton <oliver.upton@linux.dev>
parent 9fe9663e

arch/arm64/kvm/sys_regs.c

+15 −5
Original line number Diff line number Diff line
@@ -2592,6 +2592,16 @@ static unsigned int tcr2_el2_visibility(const struct kvm_vcpu *vcpu, 
	return __el2_visibility(vcpu, rd, tcr2_visibility);

}



static unsigned int fgt_visibility(const struct kvm_vcpu *vcpu,

				   const struct sys_reg_desc *rd)

{

	if (el2_visibility(vcpu, rd) == 0 &&

	    kvm_has_feat(vcpu->kvm, ID_AA64MMFR0_EL1, FGT, IMP))

		return 0;



	return REG_HIDDEN;

}



static unsigned int s1pie_visibility(const struct kvm_vcpu *vcpu,

				     const struct sys_reg_desc *rd)

{
@@ -3310,8 +3320,8 @@ static const struct sys_reg_desc sys_reg_descs[] = { 
	EL2_REG(MDCR_EL2, access_mdcr, reset_mdcr, 0),

	EL2_REG(CPTR_EL2, access_rw, reset_val, CPTR_NVHE_EL2_RES1),

	EL2_REG_VNCR(HSTR_EL2, reset_val, 0),

	EL2_REG_VNCR(HFGRTR_EL2, reset_val, 0),

	EL2_REG_VNCR(HFGWTR_EL2, reset_val, 0),

	EL2_REG_VNCR_FILT(HFGRTR_EL2, fgt_visibility),

	EL2_REG_VNCR_FILT(HFGWTR_EL2, fgt_visibility),

	EL2_REG_VNCR(HFGITR_EL2, reset_val, 0),

	EL2_REG_VNCR(HACR_EL2, reset_val, 0),
@@ -3331,9 +3341,9 @@ static const struct sys_reg_desc sys_reg_descs[] = { 
			 vncr_el2_visibility),



	{ SYS_DESC(SYS_DACR32_EL2), undef_access, reset_unknown, DACR32_EL2 },

	EL2_REG_VNCR(HDFGRTR_EL2, reset_val, 0),

	EL2_REG_VNCR(HDFGWTR_EL2, reset_val, 0),

	EL2_REG_VNCR(HAFGRTR_EL2, reset_val, 0),

	EL2_REG_VNCR_FILT(HDFGRTR_EL2, fgt_visibility),

	EL2_REG_VNCR_FILT(HDFGWTR_EL2, fgt_visibility),

	EL2_REG_VNCR_FILT(HAFGRTR_EL2, fgt_visibility),

	EL2_REG_REDIR(SPSR_EL2, reset_val, 0),

	EL2_REG_REDIR(ELR_EL2, reset_val, 0),

	{ SYS_DESC(SYS_SP_EL1), access_sp_el1},