Commit 02f10845 authored by Ricardo Koller's avatar Ricardo Koller Committed by Oliver Upton
Browse files

KVM: arm64: Add KVM_PGTABLE_WALK flags for skipping CMOs and BBM TLBIs 



Add two flags to kvm_pgtable_visit_ctx, KVM_PGTABLE_WALK_SKIP_BBM_TLBI
and KVM_PGTABLE_WALK_SKIP_CMO, to indicate that the walk should not
perform TLB invalidations (TLBIs) in break-before-make (BBM) nor cache
maintenance operations (CMO). This will be used by a future commit to
create unlinked tables not accessible to the HW page-table walker.

Signed-off-by: default avatarRicardo Koller <ricarkol@google.com>
Reviewed-by: default avatarShaoqin Huang <shahuang@redhat.com>
Reviewed-by: default avatarGavin Shan <gshan@redhat.com>
Link: https://lore.kernel.org/r/20230426172330.1439644-3-ricarkol@google.com


Signed-off-by: default avatarOliver Upton <oliver.upton@linux.dev>
parent c14d08c5

arch/arm64/include/asm/kvm_pgtable.h

+8 −0
Original line number Diff line number Diff line
@@ -195,6 +195,12 @@ typedef bool (*kvm_pgtable_force_pte_cb_t)(u64 addr, u64 end, 
 *					with other software walkers.

 * @KVM_PGTABLE_WALK_HANDLE_FAULT:	Indicates the page-table walk was

 *					invoked from a fault handler.

 * @KVM_PGTABLE_WALK_SKIP_BBM_TLBI:	Visit and update table entries

 *					without Break-before-make's

 *					TLB invalidation.

 * @KVM_PGTABLE_WALK_SKIP_CMO:		Visit and update table entries

 *					without Cache maintenance

 *					operations required.

 */

enum kvm_pgtable_walk_flags {

	KVM_PGTABLE_WALK_LEAF			= BIT(0),
@@ -202,6 +208,8 @@ enum kvm_pgtable_walk_flags { 
	KVM_PGTABLE_WALK_TABLE_POST		= BIT(2),

	KVM_PGTABLE_WALK_SHARED			= BIT(3),

	KVM_PGTABLE_WALK_HANDLE_FAULT		= BIT(4),

	KVM_PGTABLE_WALK_SKIP_BBM_TLBI		= BIT(5),

	KVM_PGTABLE_WALK_SKIP_CMO		= BIT(6),

};



struct kvm_pgtable_visit_ctx {

arch/arm64/kvm/hyp/pgtable.c

+26 −11
Original line number Diff line number Diff line
@@ -62,6 +62,16 @@ struct kvm_pgtable_walk_data { 
	u64				end;

};



static bool kvm_pgtable_walk_skip_bbm_tlbi(const struct kvm_pgtable_visit_ctx *ctx)

{

	return unlikely(ctx->flags & KVM_PGTABLE_WALK_SKIP_BBM_TLBI);

}



static bool kvm_pgtable_walk_skip_cmo(const struct kvm_pgtable_visit_ctx *ctx)

{

	return unlikely(ctx->flags & KVM_PGTABLE_WALK_SKIP_CMO);

}



static bool kvm_phys_is_valid(u64 phys)

{

	return phys < BIT(id_aa64mmfr0_parange_to_phys_shift(ID_AA64MMFR0_EL1_PARANGE_MAX));
@@ -741,14 +751,17 @@ static bool stage2_try_break_pte(const struct kvm_pgtable_visit_ctx *ctx, 
	if (!stage2_try_set_pte(ctx, KVM_INVALID_PTE_LOCKED))

		return false;



	if (!kvm_pgtable_walk_skip_bbm_tlbi(ctx)) {

		/*

	 * Perform the appropriate TLB invalidation based on the evicted pte

	 * value (if any).

		 * Perform the appropriate TLB invalidation based on the

		 * evicted pte value (if any).

		 */

		if (kvm_pte_table(ctx->old, ctx->level))

			kvm_call_hyp(__kvm_tlb_flush_vmid, mmu);

		else if (kvm_pte_valid(ctx->old))

		kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, mmu, ctx->addr, ctx->level);

			kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, mmu,

				     ctx->addr, ctx->level);

	}



	if (stage2_pte_is_counted(ctx->old))

		mm_ops->put_page(ctx->ptep);
@@ -832,11 +845,13 @@ static int stage2_map_walker_try_leaf(const struct kvm_pgtable_visit_ctx *ctx, 
		return -EAGAIN;



	/* Perform CMOs before installation of the guest stage-2 PTE */

	if (mm_ops->dcache_clean_inval_poc && stage2_pte_cacheable(pgt, new))

	if (!kvm_pgtable_walk_skip_cmo(ctx) && mm_ops->dcache_clean_inval_poc &&

	    stage2_pte_cacheable(pgt, new))

		mm_ops->dcache_clean_inval_poc(kvm_pte_follow(new, mm_ops),

					       granule);



	if (mm_ops->icache_inval_pou && stage2_pte_executable(new))

	if (!kvm_pgtable_walk_skip_cmo(ctx) && mm_ops->icache_inval_pou &&

	    stage2_pte_executable(new))

		mm_ops->icache_inval_pou(kvm_pte_follow(new, mm_ops), granule);



	stage2_make_pte(ctx, new);