On Wed, Oct 06, 2021 at 01:02:11PM +0200, Andrew Jones wrote:

On Mon, Oct 04, 2021 at 06:48:36PM +0100, Marc Zyngier wrote:

quoted

kvm_pgtable_stage2_set_owner() could be generalised into a way
to store up to 63 bits in the page tables, as long as we don't
set bit 0.

Let's just do that.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/include/asm/kvm_pgtable.h          | 12 ++++++-----
 arch/arm64/kvm/hyp/include/nvhe/mem_protect.h |  2 +-
 arch/arm64/kvm/hyp/nvhe/mem_protect.c         | 11 ++++------
 arch/arm64/kvm/hyp/nvhe/setup.c               | 10 +++++++++-
 arch/arm64/kvm/hyp/pgtable.c                  | 20 ++++++-------------
 5 files changed, 27 insertions(+), 28 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/include/asm/kvm_pgtable.h
index 027783829584..d4d3ae0b5edb 100644
--- a/arch/arm64/include/asm/kvm_pgtable.h
+++ b/arch/arm64/include/asm/kvm_pgtable.h

@@ -329,14 +329,16 @@ int kvm_pgtable_stage2_map(struct kvm_pgtable *pgt, u64 addr, u64 size,
 			   void *mc);
 
 /**
- * kvm_pgtable_stage2_set_owner() - Unmap and annotate pages in the IPA space to
- *				    track ownership.
+ * kvm_pgtable_stage2_annotate() - Unmap and annotate pages in the IPA space
+ *				   to track ownership (and more).
  * @pgt:	Page-table structure initialised by kvm_pgtable_stage2_init*().
  * @addr:	Base intermediate physical address to annotate.
  * @size:	Size of the annotated range.
  * @mc:		Cache of pre-allocated and zeroed memory from which to allocate
  *		page-table pages.
- * @owner_id:	Unique identifier for the owner of the page.
+ * @annotation:	A 63 bit value that will be stored in the page tables.
+ *		@annotation[0] must be 0, and @annotation[63:1] is stored
+ *		in the page tables.
  *
  * By default, all page-tables are owned by identifier 0. This function can be
  * used to mark portions of the IPA space as owned by other entities. When a

@@ -345,8 +347,8 @@ int kvm_pgtable_stage2_map(struct kvm_pgtable *pgt, u64 addr, u64 size,
  *
  * Return: 0 on success, negative error code on failure.
  */
-int kvm_pgtable_stage2_set_owner(struct kvm_pgtable *pgt, u64 addr, u64 size,
-				 void *mc, u8 owner_id);
+int kvm_pgtable_stage2_annotate(struct kvm_pgtable *pgt, u64 addr, u64 size,
+				void *mc, kvm_pte_t annotation);
 
 /**
  * kvm_pgtable_stage2_unmap() - Remove a mapping from a guest stage-2 page-table.

diff --git a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h
index b58c910babaf..9d2ca173ea9a 100644
--- a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h
+++ b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h

@@ -53,7 +53,7 @@ int __pkvm_host_share_hyp(u64 pfn);
 
 bool addr_is_memory(phys_addr_t phys);
 int host_stage2_idmap_locked(phys_addr_t addr, u64 size, enum kvm_pgtable_prot prot);
-int host_stage2_set_owner_locked(phys_addr_t addr, u64 size, u8 owner_id);
+int host_stage2_annotate_locked(phys_addr_t addr, u64 size, kvm_pte_t owner_id);
 int kvm_host_prepare_stage2(void *pgt_pool_base);
 void handle_host_mem_abort(struct kvm_cpu_context *host_ctxt);
 

diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
index bacd493a4eac..8cd0c3bdb911 100644
--- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c
+++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c

@@ -286,17 +286,14 @@ static int host_stage2_adjust_range(u64 addr, struct kvm_mem_range *range)
 int host_stage2_idmap_locked(phys_addr_t addr, u64 size,
 			     enum kvm_pgtable_prot prot)
 {
-	hyp_assert_lock_held(&host_kvm.lock);
-
 	return host_stage2_try(__host_stage2_idmap, addr, addr + size, prot);
 }
 
-int host_stage2_set_owner_locked(phys_addr_t addr, u64 size, u8 owner_id)
+int host_stage2_annotate_locked(phys_addr_t addr, u64 size,
+				kvm_pte_t annotation)
 {
-	hyp_assert_lock_held(&host_kvm.lock);

Hi Marc,

Why are the lock asserts getting dropped?

Ah, I see. host_stage2_try already has the same assert.

Reviewed-by: Andrew Jones <redacted>

Thanks,
drew


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel