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-rw-r--r--arch/arm64/kvm/nested.c162
1 files changed, 162 insertions, 0 deletions
diff --git a/arch/arm64/kvm/nested.c b/arch/arm64/kvm/nested.c
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+++ b/arch/arm64/kvm/nested.c
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+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2017 - Columbia University and Linaro Ltd.
+ * Author: Jintack Lim <jintack.lim@linaro.org>
+ */
+
+#include <linux/kvm.h>
+#include <linux/kvm_host.h>
+
+#include <asm/kvm_emulate.h>
+#include <asm/kvm_nested.h>
+#include <asm/sysreg.h>
+
+#include "sys_regs.h"
+
+/* Protection against the sysreg repainting madness... */
+#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.
+ */
+void access_nested_id_reg(struct kvm_vcpu *v, struct sys_reg_params *p,
+ const struct sys_reg_desc *r)
+{
+ u32 id = reg_to_encoding(r);
+ u64 val, tmp;
+
+ val = p->regval;
+
+ 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;
+
+ case SYS_ID_AA64ISAR1_EL1:
+ /* Support everything but PtrAuth and Spec Invalidation */
+ val &= ~(GENMASK_ULL(63, 56) |
+ NV_FTR(ISAR1, SPECRES) |
+ NV_FTR(ISAR1, GPI) |
+ NV_FTR(ISAR1, GPA) |
+ NV_FTR(ISAR1, API) |
+ NV_FTR(ISAR1, APA));
+ break;
+
+ 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);
+ break;
+
+ case SYS_ID_AA64PFR1_EL1:
+ /* Only support SSBS */
+ val &= NV_FTR(PFR1, SSBS);
+ break;
+
+ 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.
+ */
+ 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);
+ }
+ 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));
+ 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));
+
+ /* Force TTL support */
+ val |= FIELD_PREP(NV_FTR(MMFR2, TTL), 0b0001);
+ break;
+
+ 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);
+ }
+ break;
+
+ default:
+ /* Unknown register, just wipe it clean */
+ val = 0;
+ break;
+ }
+
+ p->regval = val;
+}