[PATCH v3 07/20] kvm: arm/arm64: Prepare for VM specific stage2 translations

On 02/07/18 11:12, Marc Zyngier wrote:

On 29/06/18 12:15, Suzuki K Poulose wrote:

quoted

Right now the stage2 page table for a VM is hard coded, assuming
an IPA of 40bits. As we are about to add support for per VM IPA,
prepare the stage2 page table helpers to accept the kvm instance
to make the right decision for the VM. No functional changes.
Adds stage2_pgd_size(kvm) to replace S2_PGD_SIZE. Also, moves
some of the definitions dependent on kvm instance to asm/kvm_mmu.h
for arm32. In that process drop the _AC() specifier constants

Cc: Marc Zyngier <redacted>
Cc: Christoffer Dall <cdall@kernel.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
Changes since V2:
  - Update commit description abuot the movement to asm/kvm_mmu.h
    for arm32
  - Drop _AC() specifiers
---
  arch/arm/include/asm/kvm_arm.h                |   3 +-
  arch/arm/include/asm/kvm_mmu.h                |  15 +++-
  arch/arm/include/asm/stage2_pgtable.h         |  42 ++++-----
  arch/arm64/include/asm/kvm_mmu.h              |   7 +-
  arch/arm64/include/asm/stage2_pgtable-nopmd.h |  18 ++--
  arch/arm64/include/asm/stage2_pgtable-nopud.h |  16 ++--
  arch/arm64/include/asm/stage2_pgtable.h       |  49 ++++++-----
  virt/kvm/arm/arm.c                            |   2 +-
  virt/kvm/arm/mmu.c                            | 119 +++++++++++++-------------
  virt/kvm/arm/vgic/vgic-kvm-device.c           |   2 +-
  10 files changed, 148 insertions(+), 125 deletions(-)

diff --git a/arch/arm/include/asm/kvm_arm.h b/arch/arm/include/asm/kvm_arm.h
index 3ab8b37..c3f1f9b 100644
--- a/arch/arm/include/asm/kvm_arm.h
+++ b/arch/arm/include/asm/kvm_arm.h

@@ -133,8 +133,7 @@
   * space.
   */
  #define KVM_PHYS_SHIFT	(40)
-#define KVM_PHYS_SIZE	(_AC(1, ULL) << KVM_PHYS_SHIFT)
-#define KVM_PHYS_MASK	(KVM_PHYS_SIZE - _AC(1, ULL))
+
  #define PTRS_PER_S2_PGD	(_AC(1, ULL) << (KVM_PHYS_SHIFT - 30))
  
  /* Virtualization Translation Control Register (VTCR) bits */

diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h
index 8553d68..f36eb20 100644
--- a/arch/arm/include/asm/kvm_mmu.h
+++ b/arch/arm/include/asm/kvm_mmu.h

@@ -36,15 +36,19 @@
  	})
  
  /*
- * KVM_MMU_CACHE_MIN_PAGES is the number of stage2 page table translation levels.
+ * kvm_mmu_cache_min_pages() is the number of stage2 page
+ * table translation levels, excluding the top level, for
+ * the given VM. Since we have a 3 level page-table, this
+ * is fixed.

I find this comment quite confusing: number of levels, but excluding the
top one? The original one was just as bad, to be honest.

Can't we just say: "kvm_mmu_cache_min_page() is the number of pages
required to install a stage-2 translation"?

Yes, that is much better.  Will change it.

quoted

diff --git a/arch/arm64/include/asm/stage2_pgtable.h b/arch/arm64/include/asm/stage2_pgtable.h
index 8b68099..057a405 100644
--- a/arch/arm64/include/asm/stage2_pgtable.h
+++ b/arch/arm64/include/asm/stage2_pgtable.h

@@ -65,10 +65,10 @@
  #define PTRS_PER_S2_PGD			(1 << (KVM_PHYS_SHIFT - S2_PGDIR_SHIFT))
  
  /*
- * KVM_MMU_CACHE_MIN_PAGES is the number of stage2 page table translation
+ * kvm_mmmu_cache_min_pages is the number of stage2 page table translation
   * levels in addition to the PGD.
   */
-#define KVM_MMU_CACHE_MIN_PAGES		(STAGE2_PGTABLE_LEVELS - 1)
+#define kvm_mmu_cache_min_pages(kvm)	(STAGE2_PGTABLE_LEVELS - 1)

Same comment as for the 32bit case.

quoted

quoted

Otherwise:

Acked-by: Marc Zyngier <redacted>

Thanks
Suzuki