Support guest-provided information information to find out about
the range of required invalidation.

Signed-off-by: Marc Zyngier <m...@kernel.org>
---
 arch/arm64/include/asm/kvm_nested.h |  1 +
 arch/arm64/kvm/nested.c             | 56 ++++++++++++++++++++
 arch/arm64/kvm/sys_regs.c           | 79 +++++++++++++++++++----------
 3 files changed, 108 insertions(+), 28 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_nested.h 
b/arch/arm64/include/asm/kvm_nested.h
index 7cd0c5b0fec9..620296206483 100644
--- a/arch/arm64/include/asm/kvm_nested.h
+++ b/arch/arm64/include/asm/kvm_nested.h
@@ -67,6 +67,7 @@ extern bool __forward_traps(struct kvm_vcpu *vcpu, unsigned 
int reg,
                            u64 control_bit);
 extern bool forward_traps(struct kvm_vcpu *vcpu, u64 control_bit);
 extern bool forward_nv_traps(struct kvm_vcpu *vcpu);
+unsigned int ttl_to_size(u8 ttl);
 
 struct sys_reg_params;
 struct sys_reg_desc;
diff --git a/arch/arm64/kvm/nested.c b/arch/arm64/kvm/nested.c
index 0ab08ee59110..4cb4831d4022 100644
--- a/arch/arm64/kvm/nested.c
+++ b/arch/arm64/kvm/nested.c
@@ -351,6 +351,62 @@ int kvm_walk_nested_s2(struct kvm_vcpu *vcpu, phys_addr_t 
gipa,
        return ret;
 }
 
+
+unsigned int ttl_to_size(u8 ttl)
+{
+       int level = ttl & 3;
+       unsigned int max_size = 0;
+
+       switch (ttl >> 2) {
+       case 0:                 /* No size information */
+               break;
+       case 1:                 /* 4kB translation granule */
+               switch (level) {
+               case 0:
+                       break;
+               case 1:
+                       max_size = SZ_1G;
+                       break;
+               case 2:
+                       max_size = SZ_2M;
+                       break;
+               case 3:
+                       max_size = SZ_4K;
+                       break;
+               }
+               break;
+       case 2:                 /* 16kB translation granule */
+               switch (level) {
+               case 0:
+               case 1:
+                       break;
+               case 2:
+                       max_size = SZ_32M;
+                       break;
+               case 3:
+                       max_size = SZ_16K;
+                       break;
+               }
+               break;
+       case 3:                 /* 64kB translation granule */
+               switch (level) {
+               case 0:
+               case 1:
+                       /* No 52bit IPA support */
+                       break;
+               case 2:
+                       max_size = SZ_512M;
+                       break;
+               case 3:
+                       max_size = SZ_64K;
+                       break;
+               }
+               break;
+       }
+
+       return max_size;
+}
+
 /* Must be called with kvm->lock held */
 struct kvm_s2_mmu *lookup_s2_mmu(struct kvm *kvm, u64 vttbr, u64 hcr)
 {
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 121b3f28cae2..1dcde0230b87 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -9,6 +9,7 @@
  *          Christoffer Dall <c.d...@virtualopensystems.com>
  */
 
+#include <linux/bitfield.h>
 #include <linux/bsearch.h>
 #include <linux/kvm_host.h>
 #include <linux/mm.h>
@@ -2583,59 +2584,81 @@ static bool handle_vmalls12e1is(struct kvm_vcpu *vcpu, 
struct sys_reg_params *p,
        return true;
 }
 
+static unsigned long compute_tlb_inval_range(struct kvm_vcpu *vcpu,
+                                            struct kvm_s2_mmu *mmu,
+                                            u64 val)
+{
+       unsigned long max_size;
+       u8 ttl = 0;
+
+       if (cpus_have_const_cap(ARM64_HAS_ARMv8_4_TTL)) {
+               ttl = FIELD_GET(GENMASK_ULL(47, 44), val);
+       }
+
+       max_size = ttl_to_size(ttl);
+
+       if (!max_size) {
+               u64 vtcr = vcpu_read_sys_reg(vcpu, VTCR_EL2);
+
+               /* Compute the maximum extent of the invalidation */
+               switch ((vtcr & VTCR_EL2_TG0_MASK)) {
+               case VTCR_EL2_TG0_4K:
+                       max_size = SZ_1G;
+                       break;
+               case VTCR_EL2_TG0_16K:
+                       max_size = SZ_32M;
+                       break;
+               case VTCR_EL2_TG0_64K:
+                       /*
+                        * No, we do not support 52bit IPA in nested yet. Once
+                        * we do, this should be 4TB.
+                        */
+                       /* FIXME: remove the 52bit PA support from the IDregs */
+                       max_size = SZ_512M;
+                       break;
+               default:
+                       BUG();
+               }
+       }
+
+       WARN_ON(!max_size);
+       return max_size;
+}
+
 static bool handle_ipas2e1is(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
                             const struct sys_reg_desc *r)
 {
        u64 vttbr = vcpu_read_sys_reg(vcpu, VTTBR_EL2);
-       u64 vtcr = vcpu_read_sys_reg(vcpu, VTCR_EL2);
        struct kvm_s2_mmu *mmu;
        u64 base_addr;
-       int max_size;
+       unsigned long max_size;
 
        /*
         * We drop a number of things from the supplied value:
         *
         * - NS bit: we're non-secure only.
         *
-        * - TTL field: We already have the granule size from the
-        *   VTCR_EL2.TG0 field, and the level is only relevant to the
-        *   guest's S2PT.
-        *
         * - IPA[51:48]: We don't support 52bit IPA just yet...
         *
         * And of course, adjust the IPA to be on an actual address.
         */
        base_addr = (p->regval & GENMASK_ULL(35, 0)) << 12;
 
-       /* Compute the maximum extent of the invalidation */
-       switch ((vtcr & VTCR_EL2_TG0_MASK)) {
-       case VTCR_EL2_TG0_4K:
-               max_size = SZ_1G;
-               break;
-       case VTCR_EL2_TG0_16K:
-               max_size = SZ_32M;
-               break;
-       case VTCR_EL2_TG0_64K:
-               /*
-                * No, we do not support 52bit IPA in nested yet. Once
-                * we do, this should be 4TB.
-                */
-               /* FIXME: remove the 52bit PA support from the IDregs */
-               max_size = SZ_512M;
-               break;
-       default:
-               BUG();
-       }
-
        spin_lock(&vcpu->kvm->mmu_lock);
 
        mmu = lookup_s2_mmu(vcpu->kvm, vttbr, HCR_VM);
-       if (mmu)
+       if (mmu) {
+               max_size = compute_tlb_inval_range(vcpu, mmu, p->regval);
+               base_addr &= ~(max_size - 1);
                kvm_unmap_stage2_range(mmu, base_addr, max_size);
+       }
 
        mmu = lookup_s2_mmu(vcpu->kvm, vttbr, 0);
-       if (mmu)
+       if (mmu) {
+               max_size = compute_tlb_inval_range(vcpu, mmu, p->regval);
+               base_addr &= ~(max_size - 1);
                kvm_unmap_stage2_range(mmu, base_addr, max_size);
+       }
 
        spin_unlock(&vcpu->kvm->mmu_lock);
 
-- 
2.20.1

_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

Reply via email to