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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /arch/arm64/kvm/hyp/nvhe/sys_regs.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/arm64/kvm/hyp/nvhe/sys_regs.c')
-rw-r--r--arch/arm64/kvm/hyp/nvhe/sys_regs.c515
1 files changed, 515 insertions, 0 deletions
diff --git a/arch/arm64/kvm/hyp/nvhe/sys_regs.c b/arch/arm64/kvm/hyp/nvhe/sys_regs.c
new file mode 100644
index 000000000..3d5121ee3
--- /dev/null
+++ b/arch/arm64/kvm/hyp/nvhe/sys_regs.c
@@ -0,0 +1,515 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2021 Google LLC
+ * Author: Fuad Tabba <tabba@google.com>
+ */
+
+#include <linux/irqchip/arm-gic-v3.h>
+
+#include <asm/kvm_asm.h>
+#include <asm/kvm_mmu.h>
+
+#include <hyp/adjust_pc.h>
+
+#include <nvhe/fixed_config.h>
+
+#include "../../sys_regs.h"
+
+/*
+ * Copies of the host's CPU features registers holding sanitized values at hyp.
+ */
+u64 id_aa64pfr0_el1_sys_val;
+u64 id_aa64pfr1_el1_sys_val;
+u64 id_aa64isar0_el1_sys_val;
+u64 id_aa64isar1_el1_sys_val;
+u64 id_aa64isar2_el1_sys_val;
+u64 id_aa64mmfr0_el1_sys_val;
+u64 id_aa64mmfr1_el1_sys_val;
+u64 id_aa64mmfr2_el1_sys_val;
+
+/*
+ * Inject an unknown/undefined exception to an AArch64 guest while most of its
+ * sysregs are live.
+ */
+static void inject_undef64(struct kvm_vcpu *vcpu)
+{
+ u64 esr = (ESR_ELx_EC_UNKNOWN << ESR_ELx_EC_SHIFT);
+
+ *vcpu_pc(vcpu) = read_sysreg_el2(SYS_ELR);
+ *vcpu_cpsr(vcpu) = read_sysreg_el2(SYS_SPSR);
+
+ kvm_pend_exception(vcpu, EXCEPT_AA64_EL1_SYNC);
+
+ __kvm_adjust_pc(vcpu);
+
+ write_sysreg_el1(esr, SYS_ESR);
+ write_sysreg_el1(read_sysreg_el2(SYS_ELR), SYS_ELR);
+ write_sysreg_el2(*vcpu_pc(vcpu), SYS_ELR);
+ write_sysreg_el2(*vcpu_cpsr(vcpu), SYS_SPSR);
+}
+
+/*
+ * Returns the restricted features values of the feature register based on the
+ * limitations in restrict_fields.
+ * A feature id field value of 0b0000 does not impose any restrictions.
+ * Note: Use only for unsigned feature field values.
+ */
+static u64 get_restricted_features_unsigned(u64 sys_reg_val,
+ u64 restrict_fields)
+{
+ u64 value = 0UL;
+ u64 mask = GENMASK_ULL(ARM64_FEATURE_FIELD_BITS - 1, 0);
+
+ /*
+ * According to the Arm Architecture Reference Manual, feature fields
+ * use increasing values to indicate increases in functionality.
+ * Iterate over the restricted feature fields and calculate the minimum
+ * unsigned value between the one supported by the system, and what the
+ * value is being restricted to.
+ */
+ while (sys_reg_val && restrict_fields) {
+ value |= min(sys_reg_val & mask, restrict_fields & mask);
+ sys_reg_val &= ~mask;
+ restrict_fields &= ~mask;
+ mask <<= ARM64_FEATURE_FIELD_BITS;
+ }
+
+ return value;
+}
+
+/*
+ * Functions that return the value of feature id registers for protected VMs
+ * based on allowed features, system features, and KVM support.
+ */
+
+static u64 get_pvm_id_aa64pfr0(const struct kvm_vcpu *vcpu)
+{
+ u64 set_mask = 0;
+ u64 allow_mask = PVM_ID_AA64PFR0_ALLOW;
+
+ set_mask |= get_restricted_features_unsigned(id_aa64pfr0_el1_sys_val,
+ PVM_ID_AA64PFR0_RESTRICT_UNSIGNED);
+
+ return (id_aa64pfr0_el1_sys_val & allow_mask) | set_mask;
+}
+
+static u64 get_pvm_id_aa64pfr1(const struct kvm_vcpu *vcpu)
+{
+ const struct kvm *kvm = (const struct kvm *)kern_hyp_va(vcpu->kvm);
+ u64 allow_mask = PVM_ID_AA64PFR1_ALLOW;
+
+ if (!kvm_has_mte(kvm))
+ allow_mask &= ~ARM64_FEATURE_MASK(ID_AA64PFR1_EL1_MTE);
+
+ return id_aa64pfr1_el1_sys_val & allow_mask;
+}
+
+static u64 get_pvm_id_aa64zfr0(const struct kvm_vcpu *vcpu)
+{
+ /*
+ * No support for Scalable Vectors, therefore, hyp has no sanitized
+ * copy of the feature id register.
+ */
+ BUILD_BUG_ON(PVM_ID_AA64ZFR0_ALLOW != 0ULL);
+ return 0;
+}
+
+static u64 get_pvm_id_aa64dfr0(const struct kvm_vcpu *vcpu)
+{
+ /*
+ * No support for debug, including breakpoints, and watchpoints,
+ * therefore, pKVM has no sanitized copy of the feature id register.
+ */
+ BUILD_BUG_ON(PVM_ID_AA64DFR0_ALLOW != 0ULL);
+ return 0;
+}
+
+static u64 get_pvm_id_aa64dfr1(const struct kvm_vcpu *vcpu)
+{
+ /*
+ * No support for debug, therefore, hyp has no sanitized copy of the
+ * feature id register.
+ */
+ BUILD_BUG_ON(PVM_ID_AA64DFR1_ALLOW != 0ULL);
+ return 0;
+}
+
+static u64 get_pvm_id_aa64afr0(const struct kvm_vcpu *vcpu)
+{
+ /*
+ * No support for implementation defined features, therefore, hyp has no
+ * sanitized copy of the feature id register.
+ */
+ BUILD_BUG_ON(PVM_ID_AA64AFR0_ALLOW != 0ULL);
+ return 0;
+}
+
+static u64 get_pvm_id_aa64afr1(const struct kvm_vcpu *vcpu)
+{
+ /*
+ * No support for implementation defined features, therefore, hyp has no
+ * sanitized copy of the feature id register.
+ */
+ BUILD_BUG_ON(PVM_ID_AA64AFR1_ALLOW != 0ULL);
+ return 0;
+}
+
+static u64 get_pvm_id_aa64isar0(const struct kvm_vcpu *vcpu)
+{
+ return id_aa64isar0_el1_sys_val & PVM_ID_AA64ISAR0_ALLOW;
+}
+
+static u64 get_pvm_id_aa64isar1(const struct kvm_vcpu *vcpu)
+{
+ u64 allow_mask = PVM_ID_AA64ISAR1_ALLOW;
+
+ if (!vcpu_has_ptrauth(vcpu))
+ allow_mask &= ~(ARM64_FEATURE_MASK(ID_AA64ISAR1_EL1_APA) |
+ ARM64_FEATURE_MASK(ID_AA64ISAR1_EL1_API) |
+ ARM64_FEATURE_MASK(ID_AA64ISAR1_EL1_GPA) |
+ ARM64_FEATURE_MASK(ID_AA64ISAR1_EL1_GPI));
+
+ return id_aa64isar1_el1_sys_val & allow_mask;
+}
+
+static u64 get_pvm_id_aa64isar2(const struct kvm_vcpu *vcpu)
+{
+ u64 allow_mask = PVM_ID_AA64ISAR2_ALLOW;
+
+ if (!vcpu_has_ptrauth(vcpu))
+ allow_mask &= ~(ARM64_FEATURE_MASK(ID_AA64ISAR2_EL1_APA3) |
+ ARM64_FEATURE_MASK(ID_AA64ISAR2_EL1_GPA3));
+
+ return id_aa64isar2_el1_sys_val & allow_mask;
+}
+
+static u64 get_pvm_id_aa64mmfr0(const struct kvm_vcpu *vcpu)
+{
+ u64 set_mask;
+
+ set_mask = get_restricted_features_unsigned(id_aa64mmfr0_el1_sys_val,
+ PVM_ID_AA64MMFR0_RESTRICT_UNSIGNED);
+
+ return (id_aa64mmfr0_el1_sys_val & PVM_ID_AA64MMFR0_ALLOW) | set_mask;
+}
+
+static u64 get_pvm_id_aa64mmfr1(const struct kvm_vcpu *vcpu)
+{
+ return id_aa64mmfr1_el1_sys_val & PVM_ID_AA64MMFR1_ALLOW;
+}
+
+static u64 get_pvm_id_aa64mmfr2(const struct kvm_vcpu *vcpu)
+{
+ return id_aa64mmfr2_el1_sys_val & PVM_ID_AA64MMFR2_ALLOW;
+}
+
+/* Read a sanitized cpufeature ID register by its encoding */
+u64 pvm_read_id_reg(const struct kvm_vcpu *vcpu, u32 id)
+{
+ switch (id) {
+ case SYS_ID_AA64PFR0_EL1:
+ return get_pvm_id_aa64pfr0(vcpu);
+ case SYS_ID_AA64PFR1_EL1:
+ return get_pvm_id_aa64pfr1(vcpu);
+ case SYS_ID_AA64ZFR0_EL1:
+ return get_pvm_id_aa64zfr0(vcpu);
+ case SYS_ID_AA64DFR0_EL1:
+ return get_pvm_id_aa64dfr0(vcpu);
+ case SYS_ID_AA64DFR1_EL1:
+ return get_pvm_id_aa64dfr1(vcpu);
+ case SYS_ID_AA64AFR0_EL1:
+ return get_pvm_id_aa64afr0(vcpu);
+ case SYS_ID_AA64AFR1_EL1:
+ return get_pvm_id_aa64afr1(vcpu);
+ case SYS_ID_AA64ISAR0_EL1:
+ return get_pvm_id_aa64isar0(vcpu);
+ case SYS_ID_AA64ISAR1_EL1:
+ return get_pvm_id_aa64isar1(vcpu);
+ case SYS_ID_AA64ISAR2_EL1:
+ return get_pvm_id_aa64isar2(vcpu);
+ case SYS_ID_AA64MMFR0_EL1:
+ return get_pvm_id_aa64mmfr0(vcpu);
+ case SYS_ID_AA64MMFR1_EL1:
+ return get_pvm_id_aa64mmfr1(vcpu);
+ case SYS_ID_AA64MMFR2_EL1:
+ return get_pvm_id_aa64mmfr2(vcpu);
+ default:
+ /* Unhandled ID register, RAZ */
+ return 0;
+ }
+}
+
+static u64 read_id_reg(const struct kvm_vcpu *vcpu,
+ struct sys_reg_desc const *r)
+{
+ return pvm_read_id_reg(vcpu, reg_to_encoding(r));
+}
+
+/* Handler to RAZ/WI sysregs */
+static bool pvm_access_raz_wi(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
+ const struct sys_reg_desc *r)
+{
+ if (!p->is_write)
+ p->regval = 0;
+
+ return true;
+}
+
+/*
+ * Accessor for AArch32 feature id registers.
+ *
+ * The value of these registers is "unknown" according to the spec if AArch32
+ * isn't supported.
+ */
+static bool pvm_access_id_aarch32(struct kvm_vcpu *vcpu,
+ struct sys_reg_params *p,
+ const struct sys_reg_desc *r)
+{
+ if (p->is_write) {
+ inject_undef64(vcpu);
+ return false;
+ }
+
+ /*
+ * No support for AArch32 guests, therefore, pKVM has no sanitized copy
+ * of AArch32 feature id registers.
+ */
+ BUILD_BUG_ON(FIELD_GET(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_EL1),
+ PVM_ID_AA64PFR0_RESTRICT_UNSIGNED) > ID_AA64PFR0_EL1_ELx_64BIT_ONLY);
+
+ return pvm_access_raz_wi(vcpu, p, r);
+}
+
+/*
+ * Accessor for AArch64 feature id registers.
+ *
+ * If access is allowed, set the regval to the protected VM's view of the
+ * register and return true.
+ * Otherwise, inject an undefined exception and return false.
+ */
+static bool pvm_access_id_aarch64(struct kvm_vcpu *vcpu,
+ struct sys_reg_params *p,
+ const struct sys_reg_desc *r)
+{
+ if (p->is_write) {
+ inject_undef64(vcpu);
+ return false;
+ }
+
+ p->regval = read_id_reg(vcpu, r);
+ return true;
+}
+
+static bool pvm_gic_read_sre(struct kvm_vcpu *vcpu,
+ struct sys_reg_params *p,
+ const struct sys_reg_desc *r)
+{
+ /* pVMs only support GICv3. 'nuf said. */
+ if (!p->is_write)
+ p->regval = ICC_SRE_EL1_DIB | ICC_SRE_EL1_DFB | ICC_SRE_EL1_SRE;
+
+ return true;
+}
+
+/* Mark the specified system register as an AArch32 feature id register. */
+#define AARCH32(REG) { SYS_DESC(REG), .access = pvm_access_id_aarch32 }
+
+/* Mark the specified system register as an AArch64 feature id register. */
+#define AARCH64(REG) { SYS_DESC(REG), .access = pvm_access_id_aarch64 }
+
+/*
+ * sys_reg_desc initialiser for architecturally unallocated cpufeature ID
+ * register with encoding Op0=3, Op1=0, CRn=0, CRm=crm, Op2=op2
+ * (1 <= crm < 8, 0 <= Op2 < 8).
+ */
+#define ID_UNALLOCATED(crm, op2) { \
+ Op0(3), Op1(0), CRn(0), CRm(crm), Op2(op2), \
+ .access = pvm_access_id_aarch64, \
+}
+
+/* Mark the specified system register as Read-As-Zero/Write-Ignored */
+#define RAZ_WI(REG) { SYS_DESC(REG), .access = pvm_access_raz_wi }
+
+/* Mark the specified system register as not being handled in hyp. */
+#define HOST_HANDLED(REG) { SYS_DESC(REG), .access = NULL }
+
+/*
+ * Architected system registers.
+ * Important: Must be sorted ascending by Op0, Op1, CRn, CRm, Op2
+ *
+ * NOTE: Anything not explicitly listed here is *restricted by default*, i.e.,
+ * it will lead to injecting an exception into the guest.
+ */
+static const struct sys_reg_desc pvm_sys_reg_descs[] = {
+ /* Cache maintenance by set/way operations are restricted. */
+
+ /* Debug and Trace Registers are restricted. */
+
+ /* AArch64 mappings of the AArch32 ID registers */
+ /* CRm=1 */
+ AARCH32(SYS_ID_PFR0_EL1),
+ AARCH32(SYS_ID_PFR1_EL1),
+ AARCH32(SYS_ID_DFR0_EL1),
+ AARCH32(SYS_ID_AFR0_EL1),
+ AARCH32(SYS_ID_MMFR0_EL1),
+ AARCH32(SYS_ID_MMFR1_EL1),
+ AARCH32(SYS_ID_MMFR2_EL1),
+ AARCH32(SYS_ID_MMFR3_EL1),
+
+ /* CRm=2 */
+ AARCH32(SYS_ID_ISAR0_EL1),
+ AARCH32(SYS_ID_ISAR1_EL1),
+ AARCH32(SYS_ID_ISAR2_EL1),
+ AARCH32(SYS_ID_ISAR3_EL1),
+ AARCH32(SYS_ID_ISAR4_EL1),
+ AARCH32(SYS_ID_ISAR5_EL1),
+ AARCH32(SYS_ID_MMFR4_EL1),
+ AARCH32(SYS_ID_ISAR6_EL1),
+
+ /* CRm=3 */
+ AARCH32(SYS_MVFR0_EL1),
+ AARCH32(SYS_MVFR1_EL1),
+ AARCH32(SYS_MVFR2_EL1),
+ ID_UNALLOCATED(3,3),
+ AARCH32(SYS_ID_PFR2_EL1),
+ AARCH32(SYS_ID_DFR1_EL1),
+ AARCH32(SYS_ID_MMFR5_EL1),
+ ID_UNALLOCATED(3,7),
+
+ /* AArch64 ID registers */
+ /* CRm=4 */
+ AARCH64(SYS_ID_AA64PFR0_EL1),
+ AARCH64(SYS_ID_AA64PFR1_EL1),
+ ID_UNALLOCATED(4,2),
+ ID_UNALLOCATED(4,3),
+ AARCH64(SYS_ID_AA64ZFR0_EL1),
+ ID_UNALLOCATED(4,5),
+ ID_UNALLOCATED(4,6),
+ ID_UNALLOCATED(4,7),
+ AARCH64(SYS_ID_AA64DFR0_EL1),
+ AARCH64(SYS_ID_AA64DFR1_EL1),
+ ID_UNALLOCATED(5,2),
+ ID_UNALLOCATED(5,3),
+ AARCH64(SYS_ID_AA64AFR0_EL1),
+ AARCH64(SYS_ID_AA64AFR1_EL1),
+ ID_UNALLOCATED(5,6),
+ ID_UNALLOCATED(5,7),
+ AARCH64(SYS_ID_AA64ISAR0_EL1),
+ AARCH64(SYS_ID_AA64ISAR1_EL1),
+ AARCH64(SYS_ID_AA64ISAR2_EL1),
+ ID_UNALLOCATED(6,3),
+ ID_UNALLOCATED(6,4),
+ ID_UNALLOCATED(6,5),
+ ID_UNALLOCATED(6,6),
+ ID_UNALLOCATED(6,7),
+ AARCH64(SYS_ID_AA64MMFR0_EL1),
+ AARCH64(SYS_ID_AA64MMFR1_EL1),
+ AARCH64(SYS_ID_AA64MMFR2_EL1),
+ ID_UNALLOCATED(7,3),
+ ID_UNALLOCATED(7,4),
+ ID_UNALLOCATED(7,5),
+ ID_UNALLOCATED(7,6),
+ ID_UNALLOCATED(7,7),
+
+ /* Scalable Vector Registers are restricted. */
+
+ RAZ_WI(SYS_ERRIDR_EL1),
+ RAZ_WI(SYS_ERRSELR_EL1),
+ RAZ_WI(SYS_ERXFR_EL1),
+ RAZ_WI(SYS_ERXCTLR_EL1),
+ RAZ_WI(SYS_ERXSTATUS_EL1),
+ RAZ_WI(SYS_ERXADDR_EL1),
+ RAZ_WI(SYS_ERXMISC0_EL1),
+ RAZ_WI(SYS_ERXMISC1_EL1),
+
+ /* Performance Monitoring Registers are restricted. */
+
+ /* Limited Ordering Regions Registers are restricted. */
+
+ HOST_HANDLED(SYS_ICC_SGI1R_EL1),
+ HOST_HANDLED(SYS_ICC_ASGI1R_EL1),
+ HOST_HANDLED(SYS_ICC_SGI0R_EL1),
+ { SYS_DESC(SYS_ICC_SRE_EL1), .access = pvm_gic_read_sre, },
+
+ HOST_HANDLED(SYS_CCSIDR_EL1),
+ HOST_HANDLED(SYS_CLIDR_EL1),
+ HOST_HANDLED(SYS_CSSELR_EL1),
+ HOST_HANDLED(SYS_CTR_EL0),
+
+ /* Performance Monitoring Registers are restricted. */
+
+ /* Activity Monitoring Registers are restricted. */
+
+ HOST_HANDLED(SYS_CNTP_TVAL_EL0),
+ HOST_HANDLED(SYS_CNTP_CTL_EL0),
+ HOST_HANDLED(SYS_CNTP_CVAL_EL0),
+
+ /* Performance Monitoring Registers are restricted. */
+};
+
+/*
+ * Checks that the sysreg table is unique and in-order.
+ *
+ * Returns 0 if the table is consistent, or 1 otherwise.
+ */
+int kvm_check_pvm_sysreg_table(void)
+{
+ unsigned int i;
+
+ for (i = 1; i < ARRAY_SIZE(pvm_sys_reg_descs); i++) {
+ if (cmp_sys_reg(&pvm_sys_reg_descs[i-1], &pvm_sys_reg_descs[i]) >= 0)
+ return 1;
+ }
+
+ return 0;
+}
+
+/*
+ * Handler for protected VM MSR, MRS or System instruction execution.
+ *
+ * Returns true if the hypervisor has handled the exit, and control should go
+ * back to the guest, or false if it hasn't, to be handled by the host.
+ */
+bool kvm_handle_pvm_sysreg(struct kvm_vcpu *vcpu, u64 *exit_code)
+{
+ const struct sys_reg_desc *r;
+ struct sys_reg_params params;
+ unsigned long esr = kvm_vcpu_get_esr(vcpu);
+ int Rt = kvm_vcpu_sys_get_rt(vcpu);
+
+ params = esr_sys64_to_params(esr);
+ params.regval = vcpu_get_reg(vcpu, Rt);
+
+ r = find_reg(&params, pvm_sys_reg_descs, ARRAY_SIZE(pvm_sys_reg_descs));
+
+ /* Undefined (RESTRICTED). */
+ if (r == NULL) {
+ inject_undef64(vcpu);
+ return true;
+ }
+
+ /* Handled by the host (HOST_HANDLED) */
+ if (r->access == NULL)
+ return false;
+
+ /* Handled by hyp: skip instruction if instructed to do so. */
+ if (r->access(vcpu, &params, r))
+ __kvm_skip_instr(vcpu);
+
+ if (!params.is_write)
+ vcpu_set_reg(vcpu, Rt, params.regval);
+
+ return true;
+}
+
+/*
+ * Handler for protected VM restricted exceptions.
+ *
+ * Inject an undefined exception into the guest and return true to indicate that
+ * the hypervisor has handled the exit, and control should go back to the guest.
+ */
+bool kvm_handle_pvm_restricted(struct kvm_vcpu *vcpu, u64 *exit_code)
+{
+ inject_undef64(vcpu);
+ return true;
+}