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-rw-r--r--arch/arm64/kvm/nested.c1002
1 files changed, 882 insertions, 120 deletions
diff --git a/arch/arm64/kvm/nested.c b/arch/arm64/kvm/nested.c
index bae8536cbf00..de789e0f1ae9 100644
--- a/arch/arm64/kvm/nested.c
+++ b/arch/arm64/kvm/nested.c
@@ -4,10 +4,13 @@
* Author: Jintack Lim <jintack.lim@linaro.org>
*/
+#include <linux/bitfield.h>
#include <linux/kvm.h>
#include <linux/kvm_host.h>
+#include <asm/kvm_arm.h>
#include <asm/kvm_emulate.h>
+#include <asm/kvm_mmu.h>
#include <asm/kvm_nested.h>
#include <asm/sysreg.h>
@@ -17,149 +20,910 @@
#define NV_FTR(r, f) ID_AA64##r##_EL1_##f
/*
- * Our emulated CPU doesn't support all the possible features. For the
- * sake of simplicity (and probably mental sanity), wipe out a number
- * of feature bits we don't intend to support for the time being.
- * This list should get updated as new features get added to the NV
- * support, and new extension to the architecture.
+ * Ratio of live shadow S2 MMU per vcpu. This is a trade-off between
+ * memory usage and potential number of different sets of S2 PTs in
+ * the guests. Running out of S2 MMUs only affects performance (we
+ * will invalidate them more often).
*/
-static u64 limit_nv_id_reg(u32 id, u64 val)
+#define S2_MMU_PER_VCPU 2
+
+void kvm_init_nested(struct kvm *kvm)
{
- u64 tmp;
+ kvm->arch.nested_mmus = NULL;
+ kvm->arch.nested_mmus_size = 0;
+}
- switch (id) {
- case SYS_ID_AA64ISAR0_EL1:
- /* Support everything but TME, O.S. and Range TLBIs */
- val &= ~(NV_FTR(ISAR0, TLB) |
- NV_FTR(ISAR0, TME));
- break;
+static int init_nested_s2_mmu(struct kvm *kvm, struct kvm_s2_mmu *mmu)
+{
+ /*
+ * We only initialise the IPA range on the canonical MMU, which
+ * defines the contract between KVM and userspace on where the
+ * "hardware" is in the IPA space. This affects the validity of MMIO
+ * exits forwarded to userspace, for example.
+ *
+ * For nested S2s, we use the PARange as exposed to the guest, as it
+ * is allowed to use it at will to expose whatever memory map it
+ * wants to its own guests as it would be on real HW.
+ */
+ return kvm_init_stage2_mmu(kvm, mmu, kvm_get_pa_bits(kvm));
+}
- case SYS_ID_AA64ISAR1_EL1:
- /* Support everything but Spec Invalidation */
- val &= ~(GENMASK_ULL(63, 56) |
- NV_FTR(ISAR1, SPECRES));
- break;
+int kvm_vcpu_init_nested(struct kvm_vcpu *vcpu)
+{
+ struct kvm *kvm = vcpu->kvm;
+ struct kvm_s2_mmu *tmp;
+ int num_mmus, ret = 0;
+
+ /*
+ * Let's treat memory allocation failures as benign: If we fail to
+ * allocate anything, return an error and keep the allocated array
+ * alive. Userspace may try to recover by intializing the vcpu
+ * again, and there is no reason to affect the whole VM for this.
+ */
+ num_mmus = atomic_read(&kvm->online_vcpus) * S2_MMU_PER_VCPU;
+ tmp = kvrealloc(kvm->arch.nested_mmus,
+ size_mul(sizeof(*kvm->arch.nested_mmus), kvm->arch.nested_mmus_size),
+ size_mul(sizeof(*kvm->arch.nested_mmus), num_mmus),
+ GFP_KERNEL_ACCOUNT | __GFP_ZERO);
+ if (!tmp)
+ return -ENOMEM;
+
+ /*
+ * If we went through a realocation, adjust the MMU back-pointers in
+ * the previously initialised kvm_pgtable structures.
+ */
+ if (kvm->arch.nested_mmus != tmp)
+ for (int i = 0; i < kvm->arch.nested_mmus_size; i++)
+ tmp[i].pgt->mmu = &tmp[i];
+
+ for (int i = kvm->arch.nested_mmus_size; !ret && i < num_mmus; i++)
+ ret = init_nested_s2_mmu(kvm, &tmp[i]);
+
+ if (ret) {
+ for (int i = kvm->arch.nested_mmus_size; i < num_mmus; i++)
+ kvm_free_stage2_pgd(&tmp[i]);
+
+ return ret;
+ }
- case SYS_ID_AA64PFR0_EL1:
- /* No AMU, MPAM, S-EL2, RAS or SVE */
- val &= ~(GENMASK_ULL(55, 52) |
- NV_FTR(PFR0, AMU) |
- NV_FTR(PFR0, MPAM) |
- NV_FTR(PFR0, SEL2) |
- NV_FTR(PFR0, RAS) |
- NV_FTR(PFR0, SVE) |
- NV_FTR(PFR0, EL3) |
- NV_FTR(PFR0, EL2) |
- NV_FTR(PFR0, EL1));
- /* 64bit EL1/EL2/EL3 only */
- val |= FIELD_PREP(NV_FTR(PFR0, EL1), 0b0001);
- val |= FIELD_PREP(NV_FTR(PFR0, EL2), 0b0001);
- val |= FIELD_PREP(NV_FTR(PFR0, EL3), 0b0001);
+ kvm->arch.nested_mmus_size = num_mmus;
+ kvm->arch.nested_mmus = tmp;
+
+ return 0;
+}
+
+struct s2_walk_info {
+ int (*read_desc)(phys_addr_t pa, u64 *desc, void *data);
+ void *data;
+ u64 baddr;
+ unsigned int max_oa_bits;
+ unsigned int pgshift;
+ unsigned int sl;
+ unsigned int t0sz;
+ bool be;
+};
+
+static unsigned int ps_to_output_size(unsigned int ps)
+{
+ switch (ps) {
+ case 0: return 32;
+ case 1: return 36;
+ case 2: return 40;
+ case 3: return 42;
+ case 4: return 44;
+ case 5:
+ default:
+ return 48;
+ }
+}
+
+static u32 compute_fsc(int level, u32 fsc)
+{
+ return fsc | (level & 0x3);
+}
+
+static int esr_s2_fault(struct kvm_vcpu *vcpu, int level, u32 fsc)
+{
+ u32 esr;
+
+ esr = kvm_vcpu_get_esr(vcpu) & ~ESR_ELx_FSC;
+ esr |= compute_fsc(level, fsc);
+ return esr;
+}
+
+static int get_ia_size(struct s2_walk_info *wi)
+{
+ return 64 - wi->t0sz;
+}
+
+static int check_base_s2_limits(struct s2_walk_info *wi,
+ int level, int input_size, int stride)
+{
+ int start_size, ia_size;
+
+ ia_size = get_ia_size(wi);
+
+ /* Check translation limits */
+ switch (BIT(wi->pgshift)) {
+ case SZ_64K:
+ if (level == 0 || (level == 1 && ia_size <= 42))
+ return -EFAULT;
break;
+ case SZ_16K:
+ if (level == 0 || (level == 1 && ia_size <= 40))
+ return -EFAULT;
+ break;
+ case SZ_4K:
+ if (level < 0 || (level == 0 && ia_size <= 42))
+ return -EFAULT;
+ break;
+ }
+
+ /* Check input size limits */
+ if (input_size > ia_size)
+ return -EFAULT;
+
+ /* Check number of entries in starting level table */
+ start_size = input_size - ((3 - level) * stride + wi->pgshift);
+ if (start_size < 1 || start_size > stride + 4)
+ return -EFAULT;
+
+ return 0;
+}
+
+/* Check if output is within boundaries */
+static int check_output_size(struct s2_walk_info *wi, phys_addr_t output)
+{
+ unsigned int output_size = wi->max_oa_bits;
+
+ if (output_size != 48 && (output & GENMASK_ULL(47, output_size)))
+ return -1;
+
+ return 0;
+}
- case SYS_ID_AA64PFR1_EL1:
- /* Only support BTI, SSBS, CSV2_frac */
- val &= (NV_FTR(PFR1, BT) |
- NV_FTR(PFR1, SSBS) |
- NV_FTR(PFR1, CSV2_frac));
+/*
+ * This is essentially a C-version of the pseudo code from the ARM ARM
+ * AArch64.TranslationTableWalk function. I strongly recommend looking at
+ * that pseudocode in trying to understand this.
+ *
+ * Must be called with the kvm->srcu read lock held
+ */
+static int walk_nested_s2_pgd(phys_addr_t ipa,
+ struct s2_walk_info *wi, struct kvm_s2_trans *out)
+{
+ int first_block_level, level, stride, input_size, base_lower_bound;
+ phys_addr_t base_addr;
+ unsigned int addr_top, addr_bottom;
+ u64 desc; /* page table entry */
+ int ret;
+ phys_addr_t paddr;
+
+ switch (BIT(wi->pgshift)) {
+ default:
+ case SZ_64K:
+ case SZ_16K:
+ level = 3 - wi->sl;
+ first_block_level = 2;
break;
+ case SZ_4K:
+ level = 2 - wi->sl;
+ first_block_level = 1;
+ break;
+ }
+
+ stride = wi->pgshift - 3;
+ input_size = get_ia_size(wi);
+ if (input_size > 48 || input_size < 25)
+ return -EFAULT;
+
+ ret = check_base_s2_limits(wi, level, input_size, stride);
+ if (WARN_ON(ret))
+ return ret;
+
+ base_lower_bound = 3 + input_size - ((3 - level) * stride +
+ wi->pgshift);
+ base_addr = wi->baddr & GENMASK_ULL(47, base_lower_bound);
+
+ if (check_output_size(wi, base_addr)) {
+ out->esr = compute_fsc(level, ESR_ELx_FSC_ADDRSZ);
+ return 1;
+ }
+
+ addr_top = input_size - 1;
+
+ while (1) {
+ phys_addr_t index;
+
+ addr_bottom = (3 - level) * stride + wi->pgshift;
+ index = (ipa & GENMASK_ULL(addr_top, addr_bottom))
+ >> (addr_bottom - 3);
+
+ paddr = base_addr | index;
+ ret = wi->read_desc(paddr, &desc, wi->data);
+ if (ret < 0)
+ return ret;
- case SYS_ID_AA64MMFR0_EL1:
- /* Hide ECV, ExS, Secure Memory */
- val &= ~(NV_FTR(MMFR0, ECV) |
- NV_FTR(MMFR0, EXS) |
- NV_FTR(MMFR0, TGRAN4_2) |
- NV_FTR(MMFR0, TGRAN16_2) |
- NV_FTR(MMFR0, TGRAN64_2) |
- NV_FTR(MMFR0, SNSMEM));
-
- /* Disallow unsupported S2 page sizes */
- switch (PAGE_SIZE) {
- case SZ_64K:
- val |= FIELD_PREP(NV_FTR(MMFR0, TGRAN16_2), 0b0001);
- fallthrough;
- case SZ_16K:
- val |= FIELD_PREP(NV_FTR(MMFR0, TGRAN4_2), 0b0001);
- fallthrough;
- case SZ_4K:
- /* Support everything */
- break;
- }
/*
- * Since we can't support a guest S2 page size smaller than
- * the host's own page size (due to KVM only populating its
- * own S2 using the kernel's page size), advertise the
- * limitation using FEAT_GTG.
+ * Handle reversedescriptors if endianness differs between the
+ * host and the guest hypervisor.
*/
- switch (PAGE_SIZE) {
- case SZ_4K:
- val |= FIELD_PREP(NV_FTR(MMFR0, TGRAN4_2), 0b0010);
- fallthrough;
- case SZ_16K:
- val |= FIELD_PREP(NV_FTR(MMFR0, TGRAN16_2), 0b0010);
- fallthrough;
- case SZ_64K:
- val |= FIELD_PREP(NV_FTR(MMFR0, TGRAN64_2), 0b0010);
+ if (wi->be)
+ desc = be64_to_cpu((__force __be64)desc);
+ else
+ desc = le64_to_cpu((__force __le64)desc);
+
+ /* Check for valid descriptor at this point */
+ if (!(desc & 1) || ((desc & 3) == 1 && level == 3)) {
+ out->esr = compute_fsc(level, ESR_ELx_FSC_FAULT);
+ out->upper_attr = desc;
+ return 1;
+ }
+
+ /* We're at the final level or block translation level */
+ if ((desc & 3) == 1 || level == 3)
+ break;
+
+ if (check_output_size(wi, desc)) {
+ out->esr = compute_fsc(level, ESR_ELx_FSC_ADDRSZ);
+ out->upper_attr = desc;
+ return 1;
+ }
+
+ base_addr = desc & GENMASK_ULL(47, wi->pgshift);
+
+ level += 1;
+ addr_top = addr_bottom - 1;
+ }
+
+ if (level < first_block_level) {
+ out->esr = compute_fsc(level, ESR_ELx_FSC_FAULT);
+ out->upper_attr = desc;
+ return 1;
+ }
+
+ /*
+ * We don't use the contiguous bit in the stage-2 ptes, so skip check
+ * for misprogramming of the contiguous bit.
+ */
+
+ if (check_output_size(wi, desc)) {
+ out->esr = compute_fsc(level, ESR_ELx_FSC_ADDRSZ);
+ out->upper_attr = desc;
+ return 1;
+ }
+
+ if (!(desc & BIT(10))) {
+ out->esr = compute_fsc(level, ESR_ELx_FSC_ACCESS);
+ out->upper_attr = desc;
+ return 1;
+ }
+
+ /* Calculate and return the result */
+ paddr = (desc & GENMASK_ULL(47, addr_bottom)) |
+ (ipa & GENMASK_ULL(addr_bottom - 1, 0));
+ out->output = paddr;
+ out->block_size = 1UL << ((3 - level) * stride + wi->pgshift);
+ out->readable = desc & (0b01 << 6);
+ out->writable = desc & (0b10 << 6);
+ out->level = level;
+ out->upper_attr = desc & GENMASK_ULL(63, 52);
+ return 0;
+}
+
+static int read_guest_s2_desc(phys_addr_t pa, u64 *desc, void *data)
+{
+ struct kvm_vcpu *vcpu = data;
+
+ return kvm_read_guest(vcpu->kvm, pa, desc, sizeof(*desc));
+}
+
+static void vtcr_to_walk_info(u64 vtcr, struct s2_walk_info *wi)
+{
+ wi->t0sz = vtcr & TCR_EL2_T0SZ_MASK;
+
+ switch (vtcr & VTCR_EL2_TG0_MASK) {
+ case VTCR_EL2_TG0_4K:
+ wi->pgshift = 12; break;
+ case VTCR_EL2_TG0_16K:
+ wi->pgshift = 14; break;
+ case VTCR_EL2_TG0_64K:
+ default: /* IMPDEF: treat any other value as 64k */
+ wi->pgshift = 16; break;
+ }
+
+ wi->sl = FIELD_GET(VTCR_EL2_SL0_MASK, vtcr);
+ /* Global limit for now, should eventually be per-VM */
+ wi->max_oa_bits = min(get_kvm_ipa_limit(),
+ ps_to_output_size(FIELD_GET(VTCR_EL2_PS_MASK, vtcr)));
+}
+
+int kvm_walk_nested_s2(struct kvm_vcpu *vcpu, phys_addr_t gipa,
+ struct kvm_s2_trans *result)
+{
+ u64 vtcr = vcpu_read_sys_reg(vcpu, VTCR_EL2);
+ struct s2_walk_info wi;
+ int ret;
+
+ result->esr = 0;
+
+ if (!vcpu_has_nv(vcpu))
+ return 0;
+
+ wi.read_desc = read_guest_s2_desc;
+ wi.data = vcpu;
+ wi.baddr = vcpu_read_sys_reg(vcpu, VTTBR_EL2);
+
+ vtcr_to_walk_info(vtcr, &wi);
+
+ wi.be = vcpu_read_sys_reg(vcpu, SCTLR_EL2) & SCTLR_ELx_EE;
+
+ ret = walk_nested_s2_pgd(gipa, &wi, result);
+ if (ret)
+ result->esr |= (kvm_vcpu_get_esr(vcpu) & ~ESR_ELx_FSC);
+
+ return ret;
+}
+
+static unsigned int ttl_to_size(u8 ttl)
+{
+ int level = ttl & 3;
+ int gran = (ttl >> 2) & 3;
+ unsigned int max_size = 0;
+
+ switch (gran) {
+ case TLBI_TTL_TG_4K:
+ 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;
}
- /* Cap PARange to 48bits */
- tmp = FIELD_GET(NV_FTR(MMFR0, PARANGE), val);
- if (tmp > 0b0101) {
- val &= ~NV_FTR(MMFR0, PARANGE);
- val |= FIELD_PREP(NV_FTR(MMFR0, PARANGE), 0b0101);
+ break;
+ case TLBI_TTL_TG_16K:
+ switch (level) {
+ case 0:
+ case 1:
+ break;
+ case 2:
+ max_size = SZ_32M;
+ break;
+ case 3:
+ max_size = SZ_16K;
+ break;
}
break;
-
- case SYS_ID_AA64MMFR1_EL1:
- val &= (NV_FTR(MMFR1, HCX) |
- NV_FTR(MMFR1, PAN) |
- NV_FTR(MMFR1, LO) |
- NV_FTR(MMFR1, HPDS) |
- NV_FTR(MMFR1, VH) |
- NV_FTR(MMFR1, VMIDBits));
+ case TLBI_TTL_TG_64K:
+ 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;
+ default: /* No size information */
break;
+ }
- case SYS_ID_AA64MMFR2_EL1:
- val &= ~(NV_FTR(MMFR2, BBM) |
- NV_FTR(MMFR2, TTL) |
- GENMASK_ULL(47, 44) |
- NV_FTR(MMFR2, ST) |
- NV_FTR(MMFR2, CCIDX) |
- NV_FTR(MMFR2, VARange));
+ return max_size;
+}
- /* Force TTL support */
- val |= FIELD_PREP(NV_FTR(MMFR2, TTL), 0b0001);
+/*
+ * Compute the equivalent of the TTL field by parsing the shadow PT. The
+ * granule size is extracted from the cached VTCR_EL2.TG0 while the level is
+ * retrieved from first entry carrying the level as a tag.
+ */
+static u8 get_guest_mapping_ttl(struct kvm_s2_mmu *mmu, u64 addr)
+{
+ u64 tmp, sz = 0, vtcr = mmu->tlb_vtcr;
+ kvm_pte_t pte;
+ u8 ttl, level;
+
+ lockdep_assert_held_write(&kvm_s2_mmu_to_kvm(mmu)->mmu_lock);
+
+ switch (vtcr & VTCR_EL2_TG0_MASK) {
+ case VTCR_EL2_TG0_4K:
+ ttl = (TLBI_TTL_TG_4K << 2);
+ break;
+ case VTCR_EL2_TG0_16K:
+ ttl = (TLBI_TTL_TG_16K << 2);
break;
+ case VTCR_EL2_TG0_64K:
+ default: /* IMPDEF: treat any other value as 64k */
+ ttl = (TLBI_TTL_TG_64K << 2);
+ break;
+ }
- case SYS_ID_AA64MMFR4_EL1:
- val = 0;
- if (!cpus_have_final_cap(ARM64_HAS_HCR_NV1))
- val |= FIELD_PREP(NV_FTR(MMFR4, E2H0),
- ID_AA64MMFR4_EL1_E2H0_NI_NV1);
+ tmp = addr;
+
+again:
+ /* Iteratively compute the block sizes for a particular granule size */
+ switch (vtcr & VTCR_EL2_TG0_MASK) {
+ case VTCR_EL2_TG0_4K:
+ if (sz < SZ_4K) sz = SZ_4K;
+ else if (sz < SZ_2M) sz = SZ_2M;
+ else if (sz < SZ_1G) sz = SZ_1G;
+ else sz = 0;
+ break;
+ case VTCR_EL2_TG0_16K:
+ if (sz < SZ_16K) sz = SZ_16K;
+ else if (sz < SZ_32M) sz = SZ_32M;
+ else sz = 0;
break;
+ case VTCR_EL2_TG0_64K:
+ default: /* IMPDEF: treat any other value as 64k */
+ if (sz < SZ_64K) sz = SZ_64K;
+ else if (sz < SZ_512M) sz = SZ_512M;
+ else sz = 0;
+ break;
+ }
+
+ if (sz == 0)
+ return 0;
+
+ tmp &= ~(sz - 1);
+ if (kvm_pgtable_get_leaf(mmu->pgt, tmp, &pte, NULL))
+ goto again;
+ if (!(pte & PTE_VALID))
+ goto again;
+ level = FIELD_GET(KVM_NV_GUEST_MAP_SZ, pte);
+ if (!level)
+ goto again;
+
+ ttl |= level;
- case SYS_ID_AA64DFR0_EL1:
- /* Only limited support for PMU, Debug, BPs and WPs */
- val &= (NV_FTR(DFR0, PMUVer) |
- NV_FTR(DFR0, WRPs) |
- NV_FTR(DFR0, BRPs) |
- NV_FTR(DFR0, DebugVer));
-
- /* Cap Debug to ARMv8.1 */
- tmp = FIELD_GET(NV_FTR(DFR0, DebugVer), val);
- if (tmp > 0b0111) {
- val &= ~NV_FTR(DFR0, DebugVer);
- val |= FIELD_PREP(NV_FTR(DFR0, DebugVer), 0b0111);
+ /*
+ * We now have found some level information in the shadow S2. Check
+ * that the resulting range is actually including the original IPA.
+ */
+ sz = ttl_to_size(ttl);
+ if (addr < (tmp + sz))
+ return ttl;
+
+ return 0;
+}
+
+unsigned long compute_tlb_inval_range(struct kvm_s2_mmu *mmu, u64 val)
+{
+ struct kvm *kvm = kvm_s2_mmu_to_kvm(mmu);
+ unsigned long max_size;
+ u8 ttl;
+
+ ttl = FIELD_GET(TLBI_TTL_MASK, val);
+
+ if (!ttl || !kvm_has_feat(kvm, ID_AA64MMFR2_EL1, TTL, IMP)) {
+ /* No TTL, check the shadow S2 for a hint */
+ u64 addr = (val & GENMASK_ULL(35, 0)) << 12;
+ ttl = get_guest_mapping_ttl(mmu, addr);
+ }
+
+ max_size = ttl_to_size(ttl);
+
+ if (!max_size) {
+ /* Compute the maximum extent of the invalidation */
+ switch (mmu->tlb_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:
+ default: /* IMPDEF: treat any other value as 64k */
+ /*
+ * No, we do not support 52bit IPA in nested yet. Once
+ * we do, this should be 4TB.
+ */
+ max_size = SZ_512M;
+ break;
}
- break;
+ }
- default:
- /* Unknown register, just wipe it clean */
- val = 0;
+ WARN_ON(!max_size);
+ return max_size;
+}
+
+/*
+ * We can have multiple *different* MMU contexts with the same VMID:
+ *
+ * - S2 being enabled or not, hence differing by the HCR_EL2.VM bit
+ *
+ * - Multiple vcpus using private S2s (huh huh...), hence differing by the
+ * VBBTR_EL2.BADDR address
+ *
+ * - A combination of the above...
+ *
+ * We can always identify which MMU context to pick at run-time. However,
+ * TLB invalidation involving a VMID must take action on all the TLBs using
+ * this particular VMID. This translates into applying the same invalidation
+ * operation to all the contexts that are using this VMID. Moar phun!
+ */
+void kvm_s2_mmu_iterate_by_vmid(struct kvm *kvm, u16 vmid,
+ const union tlbi_info *info,
+ void (*tlbi_callback)(struct kvm_s2_mmu *,
+ const union tlbi_info *))
+{
+ write_lock(&kvm->mmu_lock);
+
+ for (int i = 0; i < kvm->arch.nested_mmus_size; i++) {
+ struct kvm_s2_mmu *mmu = &kvm->arch.nested_mmus[i];
+
+ if (!kvm_s2_mmu_valid(mmu))
+ continue;
+
+ if (vmid == get_vmid(mmu->tlb_vttbr))
+ tlbi_callback(mmu, info);
+ }
+
+ write_unlock(&kvm->mmu_lock);
+}
+
+struct kvm_s2_mmu *lookup_s2_mmu(struct kvm_vcpu *vcpu)
+{
+ struct kvm *kvm = vcpu->kvm;
+ bool nested_stage2_enabled;
+ u64 vttbr, vtcr, hcr;
+
+ lockdep_assert_held_write(&kvm->mmu_lock);
+
+ vttbr = vcpu_read_sys_reg(vcpu, VTTBR_EL2);
+ vtcr = vcpu_read_sys_reg(vcpu, VTCR_EL2);
+ hcr = vcpu_read_sys_reg(vcpu, HCR_EL2);
+
+ nested_stage2_enabled = hcr & HCR_VM;
+
+ /* Don't consider the CnP bit for the vttbr match */
+ vttbr &= ~VTTBR_CNP_BIT;
+
+ /*
+ * Two possibilities when looking up a S2 MMU context:
+ *
+ * - either S2 is enabled in the guest, and we need a context that is
+ * S2-enabled and matches the full VTTBR (VMID+BADDR) and VTCR,
+ * which makes it safe from a TLB conflict perspective (a broken
+ * guest won't be able to generate them),
+ *
+ * - or S2 is disabled, and we need a context that is S2-disabled
+ * and matches the VMID only, as all TLBs are tagged by VMID even
+ * if S2 translation is disabled.
+ */
+ for (int i = 0; i < kvm->arch.nested_mmus_size; i++) {
+ struct kvm_s2_mmu *mmu = &kvm->arch.nested_mmus[i];
+
+ if (!kvm_s2_mmu_valid(mmu))
+ continue;
+
+ if (nested_stage2_enabled &&
+ mmu->nested_stage2_enabled &&
+ vttbr == mmu->tlb_vttbr &&
+ vtcr == mmu->tlb_vtcr)
+ return mmu;
+
+ if (!nested_stage2_enabled &&
+ !mmu->nested_stage2_enabled &&
+ get_vmid(vttbr) == get_vmid(mmu->tlb_vttbr))
+ return mmu;
+ }
+ return NULL;
+}
+
+static struct kvm_s2_mmu *get_s2_mmu_nested(struct kvm_vcpu *vcpu)
+{
+ struct kvm *kvm = vcpu->kvm;
+ struct kvm_s2_mmu *s2_mmu;
+ int i;
+
+ lockdep_assert_held_write(&vcpu->kvm->mmu_lock);
+
+ s2_mmu = lookup_s2_mmu(vcpu);
+ if (s2_mmu)
+ goto out;
+
+ /*
+ * Make sure we don't always search from the same point, or we
+ * will always reuse a potentially active context, leaving
+ * free contexts unused.
+ */
+ for (i = kvm->arch.nested_mmus_next;
+ i < (kvm->arch.nested_mmus_size + kvm->arch.nested_mmus_next);
+ i++) {
+ s2_mmu = &kvm->arch.nested_mmus[i % kvm->arch.nested_mmus_size];
+
+ if (atomic_read(&s2_mmu->refcnt) == 0)
+ break;
+ }
+ BUG_ON(atomic_read(&s2_mmu->refcnt)); /* We have struct MMUs to spare */
+
+ /* Set the scene for the next search */
+ kvm->arch.nested_mmus_next = (i + 1) % kvm->arch.nested_mmus_size;
+
+ /* Clear the old state */
+ if (kvm_s2_mmu_valid(s2_mmu))
+ kvm_stage2_unmap_range(s2_mmu, 0, kvm_phys_size(s2_mmu));
+
+ /*
+ * The virtual VMID (modulo CnP) will be used as a key when matching
+ * an existing kvm_s2_mmu.
+ *
+ * We cache VTCR at allocation time, once and for all. It'd be great
+ * if the guest didn't screw that one up, as this is not very
+ * forgiving...
+ */
+ s2_mmu->tlb_vttbr = vcpu_read_sys_reg(vcpu, VTTBR_EL2) & ~VTTBR_CNP_BIT;
+ s2_mmu->tlb_vtcr = vcpu_read_sys_reg(vcpu, VTCR_EL2);
+ s2_mmu->nested_stage2_enabled = vcpu_read_sys_reg(vcpu, HCR_EL2) & HCR_VM;
+
+out:
+ atomic_inc(&s2_mmu->refcnt);
+ return s2_mmu;
+}
+
+void kvm_init_nested_s2_mmu(struct kvm_s2_mmu *mmu)
+{
+ /* CnP being set denotes an invalid entry */
+ mmu->tlb_vttbr = VTTBR_CNP_BIT;
+ mmu->nested_stage2_enabled = false;
+ atomic_set(&mmu->refcnt, 0);
+}
+
+void kvm_vcpu_load_hw_mmu(struct kvm_vcpu *vcpu)
+{
+ if (is_hyp_ctxt(vcpu)) {
+ vcpu->arch.hw_mmu = &vcpu->kvm->arch.mmu;
+ } else {
+ write_lock(&vcpu->kvm->mmu_lock);
+ vcpu->arch.hw_mmu = get_s2_mmu_nested(vcpu);
+ write_unlock(&vcpu->kvm->mmu_lock);
+ }
+}
+
+void kvm_vcpu_put_hw_mmu(struct kvm_vcpu *vcpu)
+{
+ if (kvm_is_nested_s2_mmu(vcpu->kvm, vcpu->arch.hw_mmu)) {
+ atomic_dec(&vcpu->arch.hw_mmu->refcnt);
+ vcpu->arch.hw_mmu = NULL;
+ }
+}
+
+/*
+ * Returns non-zero if permission fault is handled by injecting it to the next
+ * level hypervisor.
+ */
+int kvm_s2_handle_perm_fault(struct kvm_vcpu *vcpu, struct kvm_s2_trans *trans)
+{
+ bool forward_fault = false;
+
+ trans->esr = 0;
+
+ if (!kvm_vcpu_trap_is_permission_fault(vcpu))
+ return 0;
+
+ if (kvm_vcpu_trap_is_iabt(vcpu)) {
+ forward_fault = !kvm_s2_trans_executable(trans);
+ } else {
+ bool write_fault = kvm_is_write_fault(vcpu);
+
+ forward_fault = ((write_fault && !trans->writable) ||
+ (!write_fault && !trans->readable));
+ }
+
+ if (forward_fault)
+ trans->esr = esr_s2_fault(vcpu, trans->level, ESR_ELx_FSC_PERM);
+
+ return forward_fault;
+}
+
+int kvm_inject_s2_fault(struct kvm_vcpu *vcpu, u64 esr_el2)
+{
+ vcpu_write_sys_reg(vcpu, vcpu->arch.fault.far_el2, FAR_EL2);
+ vcpu_write_sys_reg(vcpu, vcpu->arch.fault.hpfar_el2, HPFAR_EL2);
+
+ return kvm_inject_nested_sync(vcpu, esr_el2);
+}
+
+void kvm_nested_s2_wp(struct kvm *kvm)
+{
+ int i;
+
+ lockdep_assert_held_write(&kvm->mmu_lock);
+
+ for (i = 0; i < kvm->arch.nested_mmus_size; i++) {
+ struct kvm_s2_mmu *mmu = &kvm->arch.nested_mmus[i];
+
+ if (kvm_s2_mmu_valid(mmu))
+ kvm_stage2_wp_range(mmu, 0, kvm_phys_size(mmu));
+ }
+}
+
+void kvm_nested_s2_unmap(struct kvm *kvm)
+{
+ int i;
+
+ lockdep_assert_held_write(&kvm->mmu_lock);
+
+ for (i = 0; i < kvm->arch.nested_mmus_size; i++) {
+ struct kvm_s2_mmu *mmu = &kvm->arch.nested_mmus[i];
+
+ if (kvm_s2_mmu_valid(mmu))
+ kvm_stage2_unmap_range(mmu, 0, kvm_phys_size(mmu));
+ }
+}
+
+void kvm_nested_s2_flush(struct kvm *kvm)
+{
+ int i;
+
+ lockdep_assert_held_write(&kvm->mmu_lock);
+
+ for (i = 0; i < kvm->arch.nested_mmus_size; i++) {
+ struct kvm_s2_mmu *mmu = &kvm->arch.nested_mmus[i];
+
+ if (kvm_s2_mmu_valid(mmu))
+ kvm_stage2_flush_range(mmu, 0, kvm_phys_size(mmu));
+ }
+}
+
+void kvm_arch_flush_shadow_all(struct kvm *kvm)
+{
+ int i;
+
+ for (i = 0; i < kvm->arch.nested_mmus_size; i++) {
+ struct kvm_s2_mmu *mmu = &kvm->arch.nested_mmus[i];
+
+ if (!WARN_ON(atomic_read(&mmu->refcnt)))
+ kvm_free_stage2_pgd(mmu);
+ }
+ kfree(kvm->arch.nested_mmus);
+ kvm->arch.nested_mmus = NULL;
+ kvm->arch.nested_mmus_size = 0;
+ kvm_uninit_stage2_mmu(kvm);
+}
+
+/*
+ * Our emulated CPU doesn't support all the possible features. For the
+ * sake of simplicity (and probably mental sanity), wipe out a number
+ * of feature bits we don't intend to support for the time being.
+ * This list should get updated as new features get added to the NV
+ * support, and new extension to the architecture.
+ */
+static void limit_nv_id_regs(struct kvm *kvm)
+{
+ u64 val, tmp;
+
+ /* Support everything but TME */
+ val = kvm_read_vm_id_reg(kvm, SYS_ID_AA64ISAR0_EL1);
+ val &= ~NV_FTR(ISAR0, TME);
+ kvm_set_vm_id_reg(kvm, SYS_ID_AA64ISAR0_EL1, val);
+
+ /* Support everything but Spec Invalidation and LS64 */
+ val = kvm_read_vm_id_reg(kvm, SYS_ID_AA64ISAR1_EL1);
+ val &= ~(NV_FTR(ISAR1, LS64) |
+ NV_FTR(ISAR1, SPECRES));
+ kvm_set_vm_id_reg(kvm, SYS_ID_AA64ISAR1_EL1, val);
+
+ /* No AMU, MPAM, S-EL2, or RAS */
+ val = kvm_read_vm_id_reg(kvm, SYS_ID_AA64PFR0_EL1);
+ val &= ~(GENMASK_ULL(55, 52) |
+ NV_FTR(PFR0, AMU) |
+ NV_FTR(PFR0, MPAM) |
+ NV_FTR(PFR0, SEL2) |
+ NV_FTR(PFR0, RAS) |
+ NV_FTR(PFR0, EL3) |
+ NV_FTR(PFR0, EL2) |
+ NV_FTR(PFR0, EL1));
+ /* 64bit EL1/EL2/EL3 only */
+ val |= FIELD_PREP(NV_FTR(PFR0, EL1), 0b0001);
+ val |= FIELD_PREP(NV_FTR(PFR0, EL2), 0b0001);
+ val |= FIELD_PREP(NV_FTR(PFR0, EL3), 0b0001);
+ kvm_set_vm_id_reg(kvm, SYS_ID_AA64PFR0_EL1, val);
+
+ /* Only support BTI, SSBS, CSV2_frac */
+ val = kvm_read_vm_id_reg(kvm, SYS_ID_AA64PFR1_EL1);
+ val &= (NV_FTR(PFR1, BT) |
+ NV_FTR(PFR1, SSBS) |
+ NV_FTR(PFR1, CSV2_frac));
+ kvm_set_vm_id_reg(kvm, SYS_ID_AA64PFR1_EL1, val);
+
+ /* Hide ECV, ExS, Secure Memory */
+ val = kvm_read_vm_id_reg(kvm, SYS_ID_AA64MMFR0_EL1);
+ val &= ~(NV_FTR(MMFR0, ECV) |
+ NV_FTR(MMFR0, EXS) |
+ NV_FTR(MMFR0, TGRAN4_2) |
+ NV_FTR(MMFR0, TGRAN16_2) |
+ NV_FTR(MMFR0, TGRAN64_2) |
+ NV_FTR(MMFR0, SNSMEM));
+
+ /* Disallow unsupported S2 page sizes */
+ switch (PAGE_SIZE) {
+ case SZ_64K:
+ val |= FIELD_PREP(NV_FTR(MMFR0, TGRAN16_2), 0b0001);
+ fallthrough;
+ case SZ_16K:
+ val |= FIELD_PREP(NV_FTR(MMFR0, TGRAN4_2), 0b0001);
+ fallthrough;
+ case SZ_4K:
+ /* Support everything */
break;
}
+ /*
+ * Since we can't support a guest S2 page size smaller than
+ * the host's own page size (due to KVM only populating its
+ * own S2 using the kernel's page size), advertise the
+ * limitation using FEAT_GTG.
+ */
+ switch (PAGE_SIZE) {
+ case SZ_4K:
+ val |= FIELD_PREP(NV_FTR(MMFR0, TGRAN4_2), 0b0010);
+ fallthrough;
+ case SZ_16K:
+ val |= FIELD_PREP(NV_FTR(MMFR0, TGRAN16_2), 0b0010);
+ fallthrough;
+ case SZ_64K:
+ val |= FIELD_PREP(NV_FTR(MMFR0, TGRAN64_2), 0b0010);
+ break;
+ }
+ /* Cap PARange to 48bits */
+ tmp = FIELD_GET(NV_FTR(MMFR0, PARANGE), val);
+ if (tmp > 0b0101) {
+ val &= ~NV_FTR(MMFR0, PARANGE);
+ val |= FIELD_PREP(NV_FTR(MMFR0, PARANGE), 0b0101);
+ }
+ kvm_set_vm_id_reg(kvm, SYS_ID_AA64MMFR0_EL1, val);
+
+ val = kvm_read_vm_id_reg(kvm, SYS_ID_AA64MMFR1_EL1);
+ val &= (NV_FTR(MMFR1, HCX) |
+ NV_FTR(MMFR1, PAN) |
+ NV_FTR(MMFR1, LO) |
+ NV_FTR(MMFR1, HPDS) |
+ NV_FTR(MMFR1, VH) |
+ NV_FTR(MMFR1, VMIDBits));
+ kvm_set_vm_id_reg(kvm, SYS_ID_AA64MMFR1_EL1, val);
+
+ val = kvm_read_vm_id_reg(kvm, SYS_ID_AA64MMFR2_EL1);
+ val &= ~(NV_FTR(MMFR2, BBM) |
+ NV_FTR(MMFR2, TTL) |
+ GENMASK_ULL(47, 44) |
+ NV_FTR(MMFR2, ST) |
+ NV_FTR(MMFR2, CCIDX) |
+ NV_FTR(MMFR2, VARange));
- return val;
+ /* Force TTL support */
+ val |= FIELD_PREP(NV_FTR(MMFR2, TTL), 0b0001);
+ kvm_set_vm_id_reg(kvm, SYS_ID_AA64MMFR2_EL1, val);
+
+ val = 0;
+ if (!cpus_have_final_cap(ARM64_HAS_HCR_NV1))
+ val |= FIELD_PREP(NV_FTR(MMFR4, E2H0),
+ ID_AA64MMFR4_EL1_E2H0_NI_NV1);
+ kvm_set_vm_id_reg(kvm, SYS_ID_AA64MMFR4_EL1, val);
+
+ /* Only limited support for PMU, Debug, BPs and WPs */
+ val = kvm_read_vm_id_reg(kvm, SYS_ID_AA64DFR0_EL1);
+ val &= (NV_FTR(DFR0, PMUVer) |
+ NV_FTR(DFR0, WRPs) |
+ NV_FTR(DFR0, BRPs) |
+ NV_FTR(DFR0, DebugVer));
+
+ /* Cap Debug to ARMv8.1 */
+ tmp = FIELD_GET(NV_FTR(DFR0, DebugVer), val);
+ if (tmp > 0b0111) {
+ val &= ~NV_FTR(DFR0, DebugVer);
+ val |= FIELD_PREP(NV_FTR(DFR0, DebugVer), 0b0111);
+ }
+ kvm_set_vm_id_reg(kvm, SYS_ID_AA64DFR0_EL1, val);
}
u64 kvm_vcpu_sanitise_vncr_reg(const struct kvm_vcpu *vcpu, enum vcpu_sysreg sr)
@@ -198,15 +962,13 @@ int kvm_init_nv_sysregs(struct kvm *kvm)
goto out;
kvm->arch.sysreg_masks = kzalloc(sizeof(*(kvm->arch.sysreg_masks)),
- GFP_KERNEL);
+ GFP_KERNEL_ACCOUNT);
if (!kvm->arch.sysreg_masks) {
ret = -ENOMEM;
goto out;
}
- for (int i = 0; i < KVM_ARM_ID_REG_NUM; i++)
- kvm->arch.id_regs[i] = limit_nv_id_reg(IDX_IDREG(i),
- kvm->arch.id_regs[i]);
+ limit_nv_id_regs(kvm);
/* VTTBR_EL2 */
res0 = res1 = 0;
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-02 05:45:20 +0100