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Diffstat (limited to 'arch/riscv/kvm/vcpu_sbi_sta.c')
-rw-r--r--arch/riscv/kvm/vcpu_sbi_sta.c212
1 files changed, 212 insertions, 0 deletions
diff --git a/arch/riscv/kvm/vcpu_sbi_sta.c b/arch/riscv/kvm/vcpu_sbi_sta.c
new file mode 100644
index 0000000000..d8cf9ca28c
--- /dev/null
+++ b/arch/riscv/kvm/vcpu_sbi_sta.c
@@ -0,0 +1,212 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2023 Ventana Micro Systems Inc.
+ */
+
+#include <linux/kconfig.h>
+#include <linux/kernel.h>
+#include <linux/kvm_host.h>
+#include <linux/mm.h>
+#include <linux/sizes.h>
+
+#include <asm/bug.h>
+#include <asm/current.h>
+#include <asm/kvm_vcpu_sbi.h>
+#include <asm/page.h>
+#include <asm/sbi.h>
+#include <asm/uaccess.h>
+
+void kvm_riscv_vcpu_sbi_sta_reset(struct kvm_vcpu *vcpu)
+{
+ vcpu->arch.sta.shmem = INVALID_GPA;
+ vcpu->arch.sta.last_steal = 0;
+}
+
+void kvm_riscv_vcpu_record_steal_time(struct kvm_vcpu *vcpu)
+{
+ gpa_t shmem = vcpu->arch.sta.shmem;
+ u64 last_steal = vcpu->arch.sta.last_steal;
+ __le32 __user *sequence_ptr;
+ __le64 __user *steal_ptr;
+ __le32 sequence_le;
+ __le64 steal_le;
+ u32 sequence;
+ u64 steal;
+ unsigned long hva;
+ gfn_t gfn;
+
+ if (shmem == INVALID_GPA)
+ return;
+
+ /*
+ * shmem is 64-byte aligned (see the enforcement in
+ * kvm_sbi_sta_steal_time_set_shmem()) and the size of sbi_sta_struct
+ * is 64 bytes, so we know all its offsets are in the same page.
+ */
+ gfn = shmem >> PAGE_SHIFT;
+ hva = kvm_vcpu_gfn_to_hva(vcpu, gfn);
+
+ if (WARN_ON(kvm_is_error_hva(hva))) {
+ vcpu->arch.sta.shmem = INVALID_GPA;
+ return;
+ }
+
+ sequence_ptr = (__le32 __user *)(hva + offset_in_page(shmem) +
+ offsetof(struct sbi_sta_struct, sequence));
+ steal_ptr = (__le64 __user *)(hva + offset_in_page(shmem) +
+ offsetof(struct sbi_sta_struct, steal));
+
+ if (WARN_ON(get_user(sequence_le, sequence_ptr)))
+ return;
+
+ sequence = le32_to_cpu(sequence_le);
+ sequence += 1;
+
+ if (WARN_ON(put_user(cpu_to_le32(sequence), sequence_ptr)))
+ return;
+
+ if (!WARN_ON(get_user(steal_le, steal_ptr))) {
+ steal = le64_to_cpu(steal_le);
+ vcpu->arch.sta.last_steal = READ_ONCE(current->sched_info.run_delay);
+ steal += vcpu->arch.sta.last_steal - last_steal;
+ WARN_ON(put_user(cpu_to_le64(steal), steal_ptr));
+ }
+
+ sequence += 1;
+ WARN_ON(put_user(cpu_to_le32(sequence), sequence_ptr));
+
+ kvm_vcpu_mark_page_dirty(vcpu, gfn);
+}
+
+static int kvm_sbi_sta_steal_time_set_shmem(struct kvm_vcpu *vcpu)
+{
+ struct kvm_cpu_context *cp = &vcpu->arch.guest_context;
+ unsigned long shmem_phys_lo = cp->a0;
+ unsigned long shmem_phys_hi = cp->a1;
+ u32 flags = cp->a2;
+ struct sbi_sta_struct zero_sta = {0};
+ unsigned long hva;
+ bool writable;
+ gpa_t shmem;
+ int ret;
+
+ if (flags != 0)
+ return SBI_ERR_INVALID_PARAM;
+
+ if (shmem_phys_lo == SBI_STA_SHMEM_DISABLE &&
+ shmem_phys_hi == SBI_STA_SHMEM_DISABLE) {
+ vcpu->arch.sta.shmem = INVALID_GPA;
+ return 0;
+ }
+
+ if (shmem_phys_lo & (SZ_64 - 1))
+ return SBI_ERR_INVALID_PARAM;
+
+ shmem = shmem_phys_lo;
+
+ if (shmem_phys_hi != 0) {
+ if (IS_ENABLED(CONFIG_32BIT))
+ shmem |= ((gpa_t)shmem_phys_hi << 32);
+ else
+ return SBI_ERR_INVALID_ADDRESS;
+ }
+
+ hva = kvm_vcpu_gfn_to_hva_prot(vcpu, shmem >> PAGE_SHIFT, &writable);
+ if (kvm_is_error_hva(hva) || !writable)
+ return SBI_ERR_INVALID_ADDRESS;
+
+ ret = kvm_vcpu_write_guest(vcpu, shmem, &zero_sta, sizeof(zero_sta));
+ if (ret)
+ return SBI_ERR_FAILURE;
+
+ vcpu->arch.sta.shmem = shmem;
+ vcpu->arch.sta.last_steal = current->sched_info.run_delay;
+
+ return 0;
+}
+
+static int kvm_sbi_ext_sta_handler(struct kvm_vcpu *vcpu, struct kvm_run *run,
+ struct kvm_vcpu_sbi_return *retdata)
+{
+ struct kvm_cpu_context *cp = &vcpu->arch.guest_context;
+ unsigned long funcid = cp->a6;
+ int ret;
+
+ switch (funcid) {
+ case SBI_EXT_STA_STEAL_TIME_SET_SHMEM:
+ ret = kvm_sbi_sta_steal_time_set_shmem(vcpu);
+ break;
+ default:
+ ret = SBI_ERR_NOT_SUPPORTED;
+ break;
+ }
+
+ retdata->err_val = ret;
+
+ return 0;
+}
+
+static unsigned long kvm_sbi_ext_sta_probe(struct kvm_vcpu *vcpu)
+{
+ return !!sched_info_on();
+}
+
+const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_sta = {
+ .extid_start = SBI_EXT_STA,
+ .extid_end = SBI_EXT_STA,
+ .handler = kvm_sbi_ext_sta_handler,
+ .probe = kvm_sbi_ext_sta_probe,
+};
+
+int kvm_riscv_vcpu_get_reg_sbi_sta(struct kvm_vcpu *vcpu,
+ unsigned long reg_num,
+ unsigned long *reg_val)
+{
+ switch (reg_num) {
+ case KVM_REG_RISCV_SBI_STA_REG(shmem_lo):
+ *reg_val = (unsigned long)vcpu->arch.sta.shmem;
+ break;
+ case KVM_REG_RISCV_SBI_STA_REG(shmem_hi):
+ if (IS_ENABLED(CONFIG_32BIT))
+ *reg_val = upper_32_bits(vcpu->arch.sta.shmem);
+ else
+ *reg_val = 0;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+int kvm_riscv_vcpu_set_reg_sbi_sta(struct kvm_vcpu *vcpu,
+ unsigned long reg_num,
+ unsigned long reg_val)
+{
+ switch (reg_num) {
+ case KVM_REG_RISCV_SBI_STA_REG(shmem_lo):
+ if (IS_ENABLED(CONFIG_32BIT)) {
+ gpa_t hi = upper_32_bits(vcpu->arch.sta.shmem);
+
+ vcpu->arch.sta.shmem = reg_val;
+ vcpu->arch.sta.shmem |= hi << 32;
+ } else {
+ vcpu->arch.sta.shmem = reg_val;
+ }
+ break;
+ case KVM_REG_RISCV_SBI_STA_REG(shmem_hi):
+ if (IS_ENABLED(CONFIG_32BIT)) {
+ gpa_t lo = lower_32_bits(vcpu->arch.sta.shmem);
+
+ vcpu->arch.sta.shmem = ((gpa_t)reg_val << 32);
+ vcpu->arch.sta.shmem |= lo;
+ } else if (reg_val != 0) {
+ return -EINVAL;
+ }
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}