Commit fdd8e345 authored by Marc Zyngier's avatar Marc Zyngier Committed by Oliver Upton
Browse files

KVM: arm64: nv: Turn encoding ranges into discrete XArray stores 



In order to be able to store different values for member of an
encoding range, replace xa_store_range() calls with discrete
xa_store() calls and an encoding iterator.

We end-up using a bit more memory, but we gain some flexibility
that we will make use of shortly.

Take this opportunity to tidy up the error handling path.

Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
Reviewed-by: default avatarJoey Gouly <joey.gouly@arm.com>
Link: https://lore.kernel.org/r/20240214131827.2856277-11-maz@kernel.org


Signed-off-by: default avatarOliver Upton <oliver.upton@linux.dev>
parent 9958d587

arch/arm64/kvm/emulate-nested.c

+36 −13
Original line number Diff line number Diff line
@@ -1757,6 +1757,28 @@ static __init void print_nv_trap_error(const struct encoding_to_trap_config *tc, 
		err);

}



static u32 encoding_next(u32 encoding)

{

	u8 op0, op1, crn, crm, op2;



	op0 = sys_reg_Op0(encoding);

	op1 = sys_reg_Op1(encoding);

	crn = sys_reg_CRn(encoding);

	crm = sys_reg_CRm(encoding);

	op2 = sys_reg_Op2(encoding);



	if (op2 < Op2_mask)

		return sys_reg(op0, op1, crn, crm, op2 + 1);

	if (crm < CRm_mask)

		return sys_reg(op0, op1, crn, crm + 1, 0);

	if (crn < CRn_mask)

		return sys_reg(op0, op1, crn + 1, 0, 0);

	if (op1 < Op1_mask)

		return sys_reg(op0, op1 + 1, 0, 0, 0);



	return sys_reg(op0 + 1, 0, 0, 0, 0);

}



int __init populate_nv_trap_config(void)

{

	int ret = 0;
@@ -1775,25 +1797,20 @@ int __init populate_nv_trap_config(void) 
			ret = -EINVAL;

		}



		if (cgt->encoding != cgt->end) {

			prev = xa_store_range(&sr_forward_xa,

					      cgt->encoding, cgt->end,

					      xa_mk_value(cgt->tc.val),

					      GFP_KERNEL);

		} else {

			prev = xa_store(&sr_forward_xa, cgt->encoding,

		for (u32 enc = cgt->encoding; enc <= cgt->end; enc = encoding_next(enc)) {

			prev = xa_store(&sr_forward_xa, enc,

					xa_mk_value(cgt->tc.val), GFP_KERNEL);

			if (prev && !xa_is_err(prev)) {

				ret = -EINVAL;

				print_nv_trap_error(cgt, "Duplicate CGT", ret);

			}

		}



			if (xa_is_err(prev)) {

				ret = xa_err(prev);

				print_nv_trap_error(cgt, "Failed CGT insertion", ret);

			}

		}

	}



	kvm_info("nv: %ld coarse grained trap handlers\n",

		 ARRAY_SIZE(encoding_to_cgt));
@@ -1804,6 +1821,7 @@ int __init populate_nv_trap_config(void) 
	for (int i = 0; i < ARRAY_SIZE(encoding_to_fgt); i++) {

		const struct encoding_to_trap_config *fgt = &encoding_to_fgt[i];

		union trap_config tc;

		void *prev;



		if (fgt->tc.fgt >= __NR_FGT_GROUP_IDS__) {

			ret = -EINVAL;
@@ -1818,8 +1836,13 @@ int __init populate_nv_trap_config(void) 
		}



		tc.val |= fgt->tc.val;

		xa_store(&sr_forward_xa, fgt->encoding,

		prev = xa_store(&sr_forward_xa, fgt->encoding,

				xa_mk_value(tc.val), GFP_KERNEL);



		if (xa_is_err(prev)) {

			ret = xa_err(prev);

			print_nv_trap_error(fgt, "Failed FGT insertion", ret);

		}

	}



	kvm_info("nv: %ld fine grained trap handlers\n",