Commit bb4fa769 authored by Sebastian Ott's avatar Sebastian Ott Committed by Oliver Upton
Browse files

KVM: arm64: show writable masks for feature registers 



Instead of using ~0UL provide the actual writable mask for
non-id feature registers in the output of the
KVM_ARM_GET_REG_WRITABLE_MASKS ioctl.

This changes the mask for the CTR_EL0 and CLIDR_EL1 registers.

Signed-off-by: default avatarSebastian Ott <sebott@redhat.com>
Reviewed-by: default avatarEric Auger <eric.auger@redhat.com>
Link: https://lore.kernel.org/r/20240619174036.483943-9-oliver.upton@linux.dev


Signed-off-by: default avatarOliver Upton <oliver.upton@linux.dev>
parent 2843cae2

arch/arm64/kvm/sys_regs.c

+5 −14
Original line number Diff line number Diff line
@@ -2486,7 +2486,7 @@ static const struct sys_reg_desc sys_reg_descs[] = { 


	{ SYS_DESC(SYS_CCSIDR_EL1), access_ccsidr },

	{ SYS_DESC(SYS_CLIDR_EL1), access_clidr, reset_clidr, CLIDR_EL1,

	  .set_user = set_clidr },

	  .set_user = set_clidr, .val = ~CLIDR_EL1_RES0 },

	{ SYS_DESC(SYS_CCSIDR2_EL1), undef_access },

	{ SYS_DESC(SYS_SMIDR_EL1), undef_access },

	{ SYS_DESC(SYS_CSSELR_EL1), access_csselr, reset_unknown, CSSELR_EL1 },
@@ -4046,20 +4046,11 @@ int kvm_vm_ioctl_get_reg_writable_masks(struct kvm *kvm, struct reg_mask_range * 
		if (!is_feature_id_reg(encoding) || !reg->set_user)

			continue;



		/*

		 * For ID registers, we return the writable mask. Other feature

		 * registers return a full 64bit mask. That's not necessary

		 * compliant with a given revision of the architecture, but the

		 * RES0/RES1 definitions allow us to do that.

		 */

		if (is_vm_ftr_id_reg(encoding)) {

		if (!reg->val ||

			    (is_aa32_id_reg(encoding) && !kvm_supports_32bit_el0()))

		    (is_aa32_id_reg(encoding) && !kvm_supports_32bit_el0())) {

			continue;

			val = reg->val;

		} else {

			val = ~0UL;

		}

		val = reg->val;



		if (put_user(val, (masks + KVM_ARM_FEATURE_ID_RANGE_INDEX(encoding))))

			return -EFAULT;