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-rw-r--r--tools/testing/selftests/kvm/lib/riscv/handlers.S101
-rw-r--r--tools/testing/selftests/kvm/lib/riscv/processor.c517
-rw-r--r--tools/testing/selftests/kvm/lib/riscv/ucall.c32
3 files changed, 650 insertions, 0 deletions
diff --git a/tools/testing/selftests/kvm/lib/riscv/handlers.S b/tools/testing/selftests/kvm/lib/riscv/handlers.S
new file mode 100644
index 000000000000..aa0abd3f35bb
--- /dev/null
+++ b/tools/testing/selftests/kvm/lib/riscv/handlers.S
@@ -0,0 +1,101 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2023 Intel Corporation
+ */
+
+#ifndef __ASSEMBLY__
+#define __ASSEMBLY__
+#endif
+
+#include <asm/csr.h>
+
+.macro save_context
+ addi sp, sp, (-8*34)
+ sd x1, 0(sp)
+ sd x2, 8(sp)
+ sd x3, 16(sp)
+ sd x4, 24(sp)
+ sd x5, 32(sp)
+ sd x6, 40(sp)
+ sd x7, 48(sp)
+ sd x8, 56(sp)
+ sd x9, 64(sp)
+ sd x10, 72(sp)
+ sd x11, 80(sp)
+ sd x12, 88(sp)
+ sd x13, 96(sp)
+ sd x14, 104(sp)
+ sd x15, 112(sp)
+ sd x16, 120(sp)
+ sd x17, 128(sp)
+ sd x18, 136(sp)
+ sd x19, 144(sp)
+ sd x20, 152(sp)
+ sd x21, 160(sp)
+ sd x22, 168(sp)
+ sd x23, 176(sp)
+ sd x24, 184(sp)
+ sd x25, 192(sp)
+ sd x26, 200(sp)
+ sd x27, 208(sp)
+ sd x28, 216(sp)
+ sd x29, 224(sp)
+ sd x30, 232(sp)
+ sd x31, 240(sp)
+ csrr s0, CSR_SEPC
+ csrr s1, CSR_SSTATUS
+ csrr s2, CSR_SCAUSE
+ sd s0, 248(sp)
+ sd s1, 256(sp)
+ sd s2, 264(sp)
+.endm
+
+.macro restore_context
+ ld s2, 264(sp)
+ ld s1, 256(sp)
+ ld s0, 248(sp)
+ csrw CSR_SCAUSE, s2
+ csrw CSR_SSTATUS, s1
+ csrw CSR_SEPC, s0
+ ld x31, 240(sp)
+ ld x30, 232(sp)
+ ld x29, 224(sp)
+ ld x28, 216(sp)
+ ld x27, 208(sp)
+ ld x26, 200(sp)
+ ld x25, 192(sp)
+ ld x24, 184(sp)
+ ld x23, 176(sp)
+ ld x22, 168(sp)
+ ld x21, 160(sp)
+ ld x20, 152(sp)
+ ld x19, 144(sp)
+ ld x18, 136(sp)
+ ld x17, 128(sp)
+ ld x16, 120(sp)
+ ld x15, 112(sp)
+ ld x14, 104(sp)
+ ld x13, 96(sp)
+ ld x12, 88(sp)
+ ld x11, 80(sp)
+ ld x10, 72(sp)
+ ld x9, 64(sp)
+ ld x8, 56(sp)
+ ld x7, 48(sp)
+ ld x6, 40(sp)
+ ld x5, 32(sp)
+ ld x4, 24(sp)
+ ld x3, 16(sp)
+ ld x2, 8(sp)
+ ld x1, 0(sp)
+ addi sp, sp, (8*34)
+.endm
+
+.balign 4
+.global exception_vectors
+exception_vectors:
+ save_context
+ move a0, sp
+ call route_exception
+ restore_context
+ sret
diff --git a/tools/testing/selftests/kvm/lib/riscv/processor.c b/tools/testing/selftests/kvm/lib/riscv/processor.c
new file mode 100644
index 000000000000..6ae47b3d6b25
--- /dev/null
+++ b/tools/testing/selftests/kvm/lib/riscv/processor.c
@@ -0,0 +1,517 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * RISC-V code
+ *
+ * Copyright (C) 2021 Western Digital Corporation or its affiliates.
+ */
+
+#include <linux/compiler.h>
+#include <assert.h>
+
+#include "kvm_util.h"
+#include "processor.h"
+#include "ucall_common.h"
+
+#define DEFAULT_RISCV_GUEST_STACK_VADDR_MIN 0xac0000
+
+static vm_vaddr_t exception_handlers;
+
+bool __vcpu_has_ext(struct kvm_vcpu *vcpu, uint64_t ext)
+{
+ unsigned long value = 0;
+ int ret;
+
+ ret = __vcpu_get_reg(vcpu, ext, &value);
+
+ return !ret && !!value;
+}
+
+static uint64_t page_align(struct kvm_vm *vm, uint64_t v)
+{
+ return (v + vm->page_size) & ~(vm->page_size - 1);
+}
+
+static uint64_t pte_addr(struct kvm_vm *vm, uint64_t entry)
+{
+ return ((entry & PGTBL_PTE_ADDR_MASK) >> PGTBL_PTE_ADDR_SHIFT) <<
+ PGTBL_PAGE_SIZE_SHIFT;
+}
+
+static uint64_t ptrs_per_pte(struct kvm_vm *vm)
+{
+ return PGTBL_PAGE_SIZE / sizeof(uint64_t);
+}
+
+static uint64_t pte_index_mask[] = {
+ PGTBL_L0_INDEX_MASK,
+ PGTBL_L1_INDEX_MASK,
+ PGTBL_L2_INDEX_MASK,
+ PGTBL_L3_INDEX_MASK,
+};
+
+static uint32_t pte_index_shift[] = {
+ PGTBL_L0_INDEX_SHIFT,
+ PGTBL_L1_INDEX_SHIFT,
+ PGTBL_L2_INDEX_SHIFT,
+ PGTBL_L3_INDEX_SHIFT,
+};
+
+static uint64_t pte_index(struct kvm_vm *vm, vm_vaddr_t gva, int level)
+{
+ TEST_ASSERT(level > -1,
+ "Negative page table level (%d) not possible", level);
+ TEST_ASSERT(level < vm->pgtable_levels,
+ "Invalid page table level (%d)", level);
+
+ return (gva & pte_index_mask[level]) >> pte_index_shift[level];
+}
+
+void virt_arch_pgd_alloc(struct kvm_vm *vm)
+{
+ size_t nr_pages = page_align(vm, ptrs_per_pte(vm) * 8) / vm->page_size;
+
+ if (vm->pgd_created)
+ return;
+
+ vm->pgd = vm_phy_pages_alloc(vm, nr_pages,
+ KVM_GUEST_PAGE_TABLE_MIN_PADDR,
+ vm->memslots[MEM_REGION_PT]);
+ vm->pgd_created = true;
+}
+
+void virt_arch_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr)
+{
+ uint64_t *ptep, next_ppn;
+ int level = vm->pgtable_levels - 1;
+
+ TEST_ASSERT((vaddr % vm->page_size) == 0,
+ "Virtual address not on page boundary,\n"
+ " vaddr: 0x%lx vm->page_size: 0x%x", vaddr, vm->page_size);
+ TEST_ASSERT(sparsebit_is_set(vm->vpages_valid,
+ (vaddr >> vm->page_shift)),
+ "Invalid virtual address, vaddr: 0x%lx", vaddr);
+ TEST_ASSERT((paddr % vm->page_size) == 0,
+ "Physical address not on page boundary,\n"
+ " paddr: 0x%lx vm->page_size: 0x%x", paddr, vm->page_size);
+ TEST_ASSERT((paddr >> vm->page_shift) <= vm->max_gfn,
+ "Physical address beyond maximum supported,\n"
+ " paddr: 0x%lx vm->max_gfn: 0x%lx vm->page_size: 0x%x",
+ paddr, vm->max_gfn, vm->page_size);
+
+ ptep = addr_gpa2hva(vm, vm->pgd) + pte_index(vm, vaddr, level) * 8;
+ if (!*ptep) {
+ next_ppn = vm_alloc_page_table(vm) >> PGTBL_PAGE_SIZE_SHIFT;
+ *ptep = (next_ppn << PGTBL_PTE_ADDR_SHIFT) |
+ PGTBL_PTE_VALID_MASK;
+ }
+ level--;
+
+ while (level > -1) {
+ ptep = addr_gpa2hva(vm, pte_addr(vm, *ptep)) +
+ pte_index(vm, vaddr, level) * 8;
+ if (!*ptep && level > 0) {
+ next_ppn = vm_alloc_page_table(vm) >>
+ PGTBL_PAGE_SIZE_SHIFT;
+ *ptep = (next_ppn << PGTBL_PTE_ADDR_SHIFT) |
+ PGTBL_PTE_VALID_MASK;
+ }
+ level--;
+ }
+
+ paddr = paddr >> PGTBL_PAGE_SIZE_SHIFT;
+ *ptep = (paddr << PGTBL_PTE_ADDR_SHIFT) |
+ PGTBL_PTE_PERM_MASK | PGTBL_PTE_VALID_MASK;
+}
+
+vm_paddr_t addr_arch_gva2gpa(struct kvm_vm *vm, vm_vaddr_t gva)
+{
+ uint64_t *ptep;
+ int level = vm->pgtable_levels - 1;
+
+ if (!vm->pgd_created)
+ goto unmapped_gva;
+
+ ptep = addr_gpa2hva(vm, vm->pgd) + pte_index(vm, gva, level) * 8;
+ if (!ptep)
+ goto unmapped_gva;
+ level--;
+
+ while (level > -1) {
+ ptep = addr_gpa2hva(vm, pte_addr(vm, *ptep)) +
+ pte_index(vm, gva, level) * 8;
+ if (!ptep)
+ goto unmapped_gva;
+ level--;
+ }
+
+ return pte_addr(vm, *ptep) + (gva & (vm->page_size - 1));
+
+unmapped_gva:
+ TEST_FAIL("No mapping for vm virtual address gva: 0x%lx level: %d",
+ gva, level);
+ exit(1);
+}
+
+static void pte_dump(FILE *stream, struct kvm_vm *vm, uint8_t indent,
+ uint64_t page, int level)
+{
+#ifdef DEBUG
+ static const char *const type[] = { "pte", "pmd", "pud", "p4d"};
+ uint64_t pte, *ptep;
+
+ if (level < 0)
+ return;
+
+ for (pte = page; pte < page + ptrs_per_pte(vm) * 8; pte += 8) {
+ ptep = addr_gpa2hva(vm, pte);
+ if (!*ptep)
+ continue;
+ fprintf(stream, "%*s%s: %lx: %lx at %p\n", indent, "",
+ type[level], pte, *ptep, ptep);
+ pte_dump(stream, vm, indent + 1,
+ pte_addr(vm, *ptep), level - 1);
+ }
+#endif
+}
+
+void virt_arch_dump(FILE *stream, struct kvm_vm *vm, uint8_t indent)
+{
+ int level = vm->pgtable_levels - 1;
+ uint64_t pgd, *ptep;
+
+ if (!vm->pgd_created)
+ return;
+
+ for (pgd = vm->pgd; pgd < vm->pgd + ptrs_per_pte(vm) * 8; pgd += 8) {
+ ptep = addr_gpa2hva(vm, pgd);
+ if (!*ptep)
+ continue;
+ fprintf(stream, "%*spgd: %lx: %lx at %p\n", indent, "",
+ pgd, *ptep, ptep);
+ pte_dump(stream, vm, indent + 1,
+ pte_addr(vm, *ptep), level - 1);
+ }
+}
+
+void riscv_vcpu_mmu_setup(struct kvm_vcpu *vcpu)
+{
+ struct kvm_vm *vm = vcpu->vm;
+ unsigned long satp;
+
+ /*
+ * The RISC-V Sv48 MMU mode supports 56-bit physical address
+ * for 48-bit virtual address with 4KB last level page size.
+ */
+ switch (vm->mode) {
+ case VM_MODE_P52V48_4K:
+ case VM_MODE_P48V48_4K:
+ case VM_MODE_P40V48_4K:
+ break;
+ default:
+ TEST_FAIL("Unknown guest mode, mode: 0x%x", vm->mode);
+ }
+
+ satp = (vm->pgd >> PGTBL_PAGE_SIZE_SHIFT) & SATP_PPN;
+ satp |= SATP_MODE_48;
+
+ vcpu_set_reg(vcpu, RISCV_GENERAL_CSR_REG(satp), satp);
+}
+
+void vcpu_arch_dump(FILE *stream, struct kvm_vcpu *vcpu, uint8_t indent)
+{
+ struct kvm_riscv_core core;
+
+ vcpu_get_reg(vcpu, RISCV_CORE_REG(mode), &core.mode);
+ vcpu_get_reg(vcpu, RISCV_CORE_REG(regs.pc), &core.regs.pc);
+ vcpu_get_reg(vcpu, RISCV_CORE_REG(regs.ra), &core.regs.ra);
+ vcpu_get_reg(vcpu, RISCV_CORE_REG(regs.sp), &core.regs.sp);
+ vcpu_get_reg(vcpu, RISCV_CORE_REG(regs.gp), &core.regs.gp);
+ vcpu_get_reg(vcpu, RISCV_CORE_REG(regs.tp), &core.regs.tp);
+ vcpu_get_reg(vcpu, RISCV_CORE_REG(regs.t0), &core.regs.t0);
+ vcpu_get_reg(vcpu, RISCV_CORE_REG(regs.t1), &core.regs.t1);
+ vcpu_get_reg(vcpu, RISCV_CORE_REG(regs.t2), &core.regs.t2);
+ vcpu_get_reg(vcpu, RISCV_CORE_REG(regs.s0), &core.regs.s0);
+ vcpu_get_reg(vcpu, RISCV_CORE_REG(regs.s1), &core.regs.s1);
+ vcpu_get_reg(vcpu, RISCV_CORE_REG(regs.a0), &core.regs.a0);
+ vcpu_get_reg(vcpu, RISCV_CORE_REG(regs.a1), &core.regs.a1);
+ vcpu_get_reg(vcpu, RISCV_CORE_REG(regs.a2), &core.regs.a2);
+ vcpu_get_reg(vcpu, RISCV_CORE_REG(regs.a3), &core.regs.a3);
+ vcpu_get_reg(vcpu, RISCV_CORE_REG(regs.a4), &core.regs.a4);
+ vcpu_get_reg(vcpu, RISCV_CORE_REG(regs.a5), &core.regs.a5);
+ vcpu_get_reg(vcpu, RISCV_CORE_REG(regs.a6), &core.regs.a6);
+ vcpu_get_reg(vcpu, RISCV_CORE_REG(regs.a7), &core.regs.a7);
+ vcpu_get_reg(vcpu, RISCV_CORE_REG(regs.s2), &core.regs.s2);
+ vcpu_get_reg(vcpu, RISCV_CORE_REG(regs.s3), &core.regs.s3);
+ vcpu_get_reg(vcpu, RISCV_CORE_REG(regs.s4), &core.regs.s4);
+ vcpu_get_reg(vcpu, RISCV_CORE_REG(regs.s5), &core.regs.s5);
+ vcpu_get_reg(vcpu, RISCV_CORE_REG(regs.s6), &core.regs.s6);
+ vcpu_get_reg(vcpu, RISCV_CORE_REG(regs.s7), &core.regs.s7);
+ vcpu_get_reg(vcpu, RISCV_CORE_REG(regs.s8), &core.regs.s8);
+ vcpu_get_reg(vcpu, RISCV_CORE_REG(regs.s9), &core.regs.s9);
+ vcpu_get_reg(vcpu, RISCV_CORE_REG(regs.s10), &core.regs.s10);
+ vcpu_get_reg(vcpu, RISCV_CORE_REG(regs.s11), &core.regs.s11);
+ vcpu_get_reg(vcpu, RISCV_CORE_REG(regs.t3), &core.regs.t3);
+ vcpu_get_reg(vcpu, RISCV_CORE_REG(regs.t4), &core.regs.t4);
+ vcpu_get_reg(vcpu, RISCV_CORE_REG(regs.t5), &core.regs.t5);
+ vcpu_get_reg(vcpu, RISCV_CORE_REG(regs.t6), &core.regs.t6);
+
+ fprintf(stream,
+ " MODE: 0x%lx\n", core.mode);
+ fprintf(stream,
+ " PC: 0x%016lx RA: 0x%016lx SP: 0x%016lx GP: 0x%016lx\n",
+ core.regs.pc, core.regs.ra, core.regs.sp, core.regs.gp);
+ fprintf(stream,
+ " TP: 0x%016lx T0: 0x%016lx T1: 0x%016lx T2: 0x%016lx\n",
+ core.regs.tp, core.regs.t0, core.regs.t1, core.regs.t2);
+ fprintf(stream,
+ " S0: 0x%016lx S1: 0x%016lx A0: 0x%016lx A1: 0x%016lx\n",
+ core.regs.s0, core.regs.s1, core.regs.a0, core.regs.a1);
+ fprintf(stream,
+ " A2: 0x%016lx A3: 0x%016lx A4: 0x%016lx A5: 0x%016lx\n",
+ core.regs.a2, core.regs.a3, core.regs.a4, core.regs.a5);
+ fprintf(stream,
+ " A6: 0x%016lx A7: 0x%016lx S2: 0x%016lx S3: 0x%016lx\n",
+ core.regs.a6, core.regs.a7, core.regs.s2, core.regs.s3);
+ fprintf(stream,
+ " S4: 0x%016lx S5: 0x%016lx S6: 0x%016lx S7: 0x%016lx\n",
+ core.regs.s4, core.regs.s5, core.regs.s6, core.regs.s7);
+ fprintf(stream,
+ " S8: 0x%016lx S9: 0x%016lx S10: 0x%016lx S11: 0x%016lx\n",
+ core.regs.s8, core.regs.s9, core.regs.s10, core.regs.s11);
+ fprintf(stream,
+ " T3: 0x%016lx T4: 0x%016lx T5: 0x%016lx T6: 0x%016lx\n",
+ core.regs.t3, core.regs.t4, core.regs.t5, core.regs.t6);
+}
+
+static void __aligned(16) guest_unexp_trap(void)
+{
+ sbi_ecall(KVM_RISCV_SELFTESTS_SBI_EXT,
+ KVM_RISCV_SELFTESTS_SBI_UNEXP,
+ 0, 0, 0, 0, 0, 0);
+}
+
+void vcpu_arch_set_entry_point(struct kvm_vcpu *vcpu, void *guest_code)
+{
+ vcpu_set_reg(vcpu, RISCV_CORE_REG(regs.pc), (unsigned long)guest_code);
+}
+
+struct kvm_vcpu *vm_arch_vcpu_add(struct kvm_vm *vm, uint32_t vcpu_id)
+{
+ int r;
+ size_t stack_size;
+ unsigned long stack_vaddr;
+ unsigned long current_gp = 0;
+ struct kvm_mp_state mps;
+ struct kvm_vcpu *vcpu;
+
+ stack_size = vm->page_size == 4096 ? DEFAULT_STACK_PGS * vm->page_size :
+ vm->page_size;
+ stack_vaddr = __vm_vaddr_alloc(vm, stack_size,
+ DEFAULT_RISCV_GUEST_STACK_VADDR_MIN,
+ MEM_REGION_DATA);
+
+ vcpu = __vm_vcpu_add(vm, vcpu_id);
+ riscv_vcpu_mmu_setup(vcpu);
+
+ /*
+ * With SBI HSM support in KVM RISC-V, all secondary VCPUs are
+ * powered-off by default so we ensure that all secondary VCPUs
+ * are powered-on using KVM_SET_MP_STATE ioctl().
+ */
+ mps.mp_state = KVM_MP_STATE_RUNNABLE;
+ r = __vcpu_ioctl(vcpu, KVM_SET_MP_STATE, &mps);
+ TEST_ASSERT(!r, "IOCTL KVM_SET_MP_STATE failed (error %d)", r);
+
+ /* Setup global pointer of guest to be same as the host */
+ asm volatile (
+ "add %0, gp, zero" : "=r" (current_gp) : : "memory");
+ vcpu_set_reg(vcpu, RISCV_CORE_REG(regs.gp), current_gp);
+
+ /* Setup stack pointer and program counter of guest */
+ vcpu_set_reg(vcpu, RISCV_CORE_REG(regs.sp), stack_vaddr + stack_size);
+
+ /* Setup sscratch for guest_get_vcpuid() */
+ vcpu_set_reg(vcpu, RISCV_GENERAL_CSR_REG(sscratch), vcpu_id);
+
+ /* Setup default exception vector of guest */
+ vcpu_set_reg(vcpu, RISCV_GENERAL_CSR_REG(stvec), (unsigned long)guest_unexp_trap);
+
+ return vcpu;
+}
+
+void vcpu_args_set(struct kvm_vcpu *vcpu, unsigned int num, ...)
+{
+ va_list ap;
+ uint64_t id = RISCV_CORE_REG(regs.a0);
+ int i;
+
+ TEST_ASSERT(num >= 1 && num <= 8, "Unsupported number of args,\n"
+ " num: %u", num);
+
+ va_start(ap, num);
+
+ for (i = 0; i < num; i++) {
+ switch (i) {
+ case 0:
+ id = RISCV_CORE_REG(regs.a0);
+ break;
+ case 1:
+ id = RISCV_CORE_REG(regs.a1);
+ break;
+ case 2:
+ id = RISCV_CORE_REG(regs.a2);
+ break;
+ case 3:
+ id = RISCV_CORE_REG(regs.a3);
+ break;
+ case 4:
+ id = RISCV_CORE_REG(regs.a4);
+ break;
+ case 5:
+ id = RISCV_CORE_REG(regs.a5);
+ break;
+ case 6:
+ id = RISCV_CORE_REG(regs.a6);
+ break;
+ case 7:
+ id = RISCV_CORE_REG(regs.a7);
+ break;
+ }
+ vcpu_set_reg(vcpu, id, va_arg(ap, uint64_t));
+ }
+
+ va_end(ap);
+}
+
+void kvm_exit_unexpected_exception(int vector, int ec)
+{
+ ucall(UCALL_UNHANDLED, 2, vector, ec);
+}
+
+void assert_on_unhandled_exception(struct kvm_vcpu *vcpu)
+{
+ struct ucall uc;
+
+ if (get_ucall(vcpu, &uc) == UCALL_UNHANDLED) {
+ TEST_FAIL("Unexpected exception (vector:0x%lx, ec:0x%lx)",
+ uc.args[0], uc.args[1]);
+ }
+}
+
+struct handlers {
+ exception_handler_fn exception_handlers[NR_VECTORS][NR_EXCEPTIONS];
+};
+
+void route_exception(struct ex_regs *regs)
+{
+ struct handlers *handlers = (struct handlers *)exception_handlers;
+ int vector = 0, ec;
+
+ ec = regs->cause & ~CAUSE_IRQ_FLAG;
+ if (ec >= NR_EXCEPTIONS)
+ goto unexpected_exception;
+
+ /* Use the same handler for all the interrupts */
+ if (regs->cause & CAUSE_IRQ_FLAG) {
+ vector = 1;
+ ec = 0;
+ }
+
+ if (handlers && handlers->exception_handlers[vector][ec])
+ return handlers->exception_handlers[vector][ec](regs);
+
+unexpected_exception:
+ return kvm_exit_unexpected_exception(vector, ec);
+}
+
+void vcpu_init_vector_tables(struct kvm_vcpu *vcpu)
+{
+ extern char exception_vectors;
+
+ vcpu_set_reg(vcpu, RISCV_GENERAL_CSR_REG(stvec), (unsigned long)&exception_vectors);
+}
+
+void vm_init_vector_tables(struct kvm_vm *vm)
+{
+ vm->handlers = __vm_vaddr_alloc(vm, sizeof(struct handlers),
+ vm->page_size, MEM_REGION_DATA);
+
+ *(vm_vaddr_t *)addr_gva2hva(vm, (vm_vaddr_t)(&exception_handlers)) = vm->handlers;
+}
+
+void vm_install_exception_handler(struct kvm_vm *vm, int vector, exception_handler_fn handler)
+{
+ struct handlers *handlers = addr_gva2hva(vm, vm->handlers);
+
+ assert(vector < NR_EXCEPTIONS);
+ handlers->exception_handlers[0][vector] = handler;
+}
+
+void vm_install_interrupt_handler(struct kvm_vm *vm, exception_handler_fn handler)
+{
+ struct handlers *handlers = addr_gva2hva(vm, vm->handlers);
+
+ handlers->exception_handlers[1][0] = handler;
+}
+
+uint32_t guest_get_vcpuid(void)
+{
+ return csr_read(CSR_SSCRATCH);
+}
+
+struct sbiret sbi_ecall(int ext, int fid, unsigned long arg0,
+ unsigned long arg1, unsigned long arg2,
+ unsigned long arg3, unsigned long arg4,
+ unsigned long arg5)
+{
+ register uintptr_t a0 asm ("a0") = (uintptr_t)(arg0);
+ register uintptr_t a1 asm ("a1") = (uintptr_t)(arg1);
+ register uintptr_t a2 asm ("a2") = (uintptr_t)(arg2);
+ register uintptr_t a3 asm ("a3") = (uintptr_t)(arg3);
+ register uintptr_t a4 asm ("a4") = (uintptr_t)(arg4);
+ register uintptr_t a5 asm ("a5") = (uintptr_t)(arg5);
+ register uintptr_t a6 asm ("a6") = (uintptr_t)(fid);
+ register uintptr_t a7 asm ("a7") = (uintptr_t)(ext);
+ struct sbiret ret;
+
+ asm volatile (
+ "ecall"
+ : "+r" (a0), "+r" (a1)
+ : "r" (a2), "r" (a3), "r" (a4), "r" (a5), "r" (a6), "r" (a7)
+ : "memory");
+ ret.error = a0;
+ ret.value = a1;
+
+ return ret;
+}
+
+bool guest_sbi_probe_extension(int extid, long *out_val)
+{
+ struct sbiret ret;
+
+ ret = sbi_ecall(SBI_EXT_BASE, SBI_EXT_BASE_PROBE_EXT, extid,
+ 0, 0, 0, 0, 0);
+
+ __GUEST_ASSERT(!ret.error || ret.error == SBI_ERR_NOT_SUPPORTED,
+ "ret.error=%ld, ret.value=%ld\n", ret.error, ret.value);
+
+ if (ret.error == SBI_ERR_NOT_SUPPORTED)
+ return false;
+
+ if (out_val)
+ *out_val = ret.value;
+
+ return true;
+}
+
+unsigned long get_host_sbi_spec_version(void)
+{
+ struct sbiret ret;
+
+ ret = sbi_ecall(SBI_EXT_BASE, SBI_EXT_BASE_GET_SPEC_VERSION, 0,
+ 0, 0, 0, 0, 0);
+
+ GUEST_ASSERT(!ret.error);
+
+ return ret.value;
+}
diff --git a/tools/testing/selftests/kvm/lib/riscv/ucall.c b/tools/testing/selftests/kvm/lib/riscv/ucall.c
new file mode 100644
index 000000000000..b5035c63d516
--- /dev/null
+++ b/tools/testing/selftests/kvm/lib/riscv/ucall.c
@@ -0,0 +1,32 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ucall support. A ucall is a "hypercall to userspace".
+ *
+ * Copyright (C) 2021 Western Digital Corporation or its affiliates.
+ */
+
+#include <linux/kvm.h>
+
+#include "kvm_util.h"
+#include "processor.h"
+#include "sbi.h"
+
+void *ucall_arch_get_ucall(struct kvm_vcpu *vcpu)
+{
+ struct kvm_run *run = vcpu->run;
+
+ if (run->exit_reason == KVM_EXIT_RISCV_SBI &&
+ run->riscv_sbi.extension_id == KVM_RISCV_SELFTESTS_SBI_EXT) {
+ switch (run->riscv_sbi.function_id) {
+ case KVM_RISCV_SELFTESTS_SBI_UCALL:
+ return (void *)run->riscv_sbi.args[0];
+ case KVM_RISCV_SELFTESTS_SBI_UNEXP:
+ vcpu_dump(stderr, vcpu, 2);
+ TEST_ASSERT(0, "Unexpected trap taken by guest");
+ break;
+ default:
+ break;
+ }
+ }
+ return NULL;
+}