+ } else {
+ int lm = is_long_mode(vcpu);
+ u8 *blob_addr = lm ? (u8 *)(long)kvm->arch.xen_hvm_config.blob_addr_64
+ : (u8 *)(long)kvm->arch.xen_hvm_config.blob_addr_32;
+ u8 blob_size = lm ? kvm->arch.xen_hvm_config.blob_size_64
+ : kvm->arch.xen_hvm_config.blob_size_32;
+ u8 *page;
+
+ if (page_num >= blob_size)
+ return 1;
+
+ page = memdup_user(blob_addr + (page_num * PAGE_SIZE), PAGE_SIZE);
+ if (IS_ERR(page))
+ return PTR_ERR(page);
+
+ if (kvm_vcpu_write_guest(vcpu, page_addr, page, PAGE_SIZE)) {
+ kfree(page);
+ return 1;
+ }
+ }
+ return 0;
+}
+
+static int kvm_xen_hypercall_set_result(struct kvm_vcpu *vcpu, u64 result)
+{
+ kvm_rax_write(vcpu, result);
+ return kvm_skip_emulated_instruction(vcpu);
+}
+
+static int kvm_xen_hypercall_complete_userspace(struct kvm_vcpu *vcpu)
+{
+ struct kvm_run *run = vcpu->run;
+
+ if (unlikely(!kvm_is_linear_rip(vcpu, vcpu->arch.xen.hypercall_rip)))
+ return 1;
+
+ return kvm_xen_hypercall_set_result(vcpu, run->xen.u.hcall.result);
+}
+
+int kvm_xen_hypercall(struct kvm_vcpu *vcpu)
+{
+ bool longmode;
+ u64 input, params[6];
+
+ input = (u64)kvm_register_read(vcpu, VCPU_REGS_RAX);
+
+ longmode = is_64_bit_mode(vcpu);
+ if (!longmode) {
+ params[0] = (u32)kvm_rbx_read(vcpu);
+ params[1] = (u32)kvm_rcx_read(vcpu);
+ params[2] = (u32)kvm_rdx_read(vcpu);
+ params[3] = (u32)kvm_rsi_read(vcpu);
+ params[4] = (u32)kvm_rdi_read(vcpu);
+ params[5] = (u32)kvm_rbp_read(vcpu);
+ }
+#ifdef CONFIG_X86_64
+ else {
+ params[0] = (u64)kvm_rdi_read(vcpu);
+ params[1] = (u64)kvm_rsi_read(vcpu);
+ params[2] = (u64)kvm_rdx_read(vcpu);
+ params[3] = (u64)kvm_r10_read(vcpu);
+ params[4] = (u64)kvm_r8_read(vcpu);
+ params[5] = (u64)kvm_r9_read(vcpu);
+ }
+#endif
+ trace_kvm_xen_hypercall(input, params[0], params[1], params[2],
+ params[3], params[4], params[5]);
+
+ vcpu->run->exit_reason = KVM_EXIT_XEN;
+ vcpu->run->xen.type = KVM_EXIT_XEN_HCALL;
+ vcpu->run->xen.u.hcall.longmode = longmode;
+ vcpu->run->xen.u.hcall.cpl = kvm_x86_ops.get_cpl(vcpu);
+ vcpu->run->xen.u.hcall.input = input;
+ vcpu->run->xen.u.hcall.params[0] = params[0];
+ vcpu->run->xen.u.hcall.params[1] = params[1];
+ vcpu->run->xen.u.hcall.params[2] = params[2];
+ vcpu->run->xen.u.hcall.params[3] = params[3];
+ vcpu->run->xen.u.hcall.params[4] = params[4];
+ vcpu->run->xen.u.hcall.params[5] = params[5];
+ vcpu->arch.xen.hypercall_rip = kvm_get_linear_rip(vcpu);
+ vcpu->arch.complete_userspace_io =
+ kvm_xen_hypercall_complete_userspace;
+
+ return 0;
+}
diff --git a/arch/x86/kvm/xen.h b/arch/x86/kvm/xen.h
new file mode 100644
index 000000000000..81e12f716d2e
--- /dev/null
+++ b/arch/x86/kvm/xen.h
@@ -0,0 +1,21 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright © 2019 Oracle and/or its affiliates. All rights reserved.
+ * Copyright © 2020 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ * KVM Xen emulation
+ */
+
+#ifndef __ARCH_X86_KVM_XEN_H__
+#define __ARCH_X86_KVM_XEN_H__
+
+int kvm_xen_hypercall(struct kvm_vcpu *vcpu);
+int kvm_xen_hvm_config(struct kvm_vcpu *vcpu, u64 data);
+
+static inline bool kvm_xen_hypercall_enabled(struct kvm *kvm)
+{
+ return kvm->arch.xen_hvm_config.flags &
+ KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL;
+}
+
+#endif /* __ARCH_X86_KVM_XEN_H__ */
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index ca41220b40b8..00221fe56994 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -216,6 +216,20 @@ struct kvm_hyperv_exit {
} u;
};
+struct kvm_xen_exit {
+#define KVM_EXIT_XEN_HCALL 1
+ __u32 type;
+ union {
+ struct {
+ __u32 longmode;
+ __u32 cpl;
+ __u64 input;
+ __u64 result;
+ __u64 params[6];
+ } hcall;
+ } u;
+};
+
#define KVM_S390_GET_SKEYS_NONE 1
#define KVM_S390_SKEYS_MAX 1048576
@@ -250,6 +264,7 @@ struct kvm_hyperv_exit {
#define KVM_EXIT_ARM_NISV 28
#define KVM_EXIT_X86_RDMSR 29
#define KVM_EXIT_X86_WRMSR 30
+#define KVM_EXIT_XEN 31
/* For KVM_EXIT_INTERNAL_ERROR */
/* Emulate instruction failed. */
@@ -426,6 +441,8 @@ struct kvm_run {
__u32 index; /* kernel -> user */
__u64 data; /* kernel <-> user */
} msr;
+ /* KVM_EXIT_XEN */
+ struct kvm_xen_exit xen;
/* Fix the size of the union. */
char padding[256];
};
@@ -1126,6 +1143,8 @@ struct kvm_x86_mce {
#endif
#ifdef KVM_CAP_XEN_HVM
+#define KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL (1 << 1)
+
struct kvm_xen_hvm_config {
__u32 flags;
__u32 msr;
diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index 3d14ef77755e..d94abec627e6 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -59,6 +59,7 @@ TEST_GEN_PROGS_x86_64 += x86_64/xss_msr_test
TEST_GEN_PROGS_x86_64 += x86_64/debug_regs
TEST_GEN_PROGS_x86_64 += x86_64/tsc_msrs_test
TEST_GEN_PROGS_x86_64 += x86_64/user_msr_test
+TEST_GEN_PROGS_x86_64 += x86_64/xen_vmcall_test
TEST_GEN_PROGS_x86_64 += demand_paging_test
TEST_GEN_PROGS_x86_64 += dirty_log_test
TEST_GEN_PROGS_x86_64 += dirty_log_perf_test
diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index 126c6727a6b0..6e96ae47d28c 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -1654,6 +1654,7 @@ static struct exit_reason {
{KVM_EXIT_INTERNAL_ERROR, "INTERNAL_ERROR"},
{KVM_EXIT_OSI, "OSI"},
{KVM_EXIT_PAPR_HCALL, "PAPR_HCALL"},
+ {KVM_EXIT_XEN, "XEN"},
#ifdef KVM_EXIT_MEMORY_NOT_PRESENT
{KVM_EXIT_MEMORY_NOT_PRESENT, "MEMORY_NOT_PRESENT"},
#endif
diff --git a/tools/testing/selftests/kvm/x86_64/xen_vmcall_test.c b/tools/testing/selftests/kvm/x86_64/xen_vmcall_test.c
new file mode 100644
index 000000000000..3f1dd93626e5
--- /dev/null
+++ b/tools/testing/selftests/kvm/x86_64/xen_vmcall_test.c
@@ -0,0 +1,123 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * svm_vmcall_test
+ *
+ * Copyright © 2020 Amazon.com, Inc. or its affiliates.
+ *
+ * Userspace hypercall testing
+ */
+
+#include "test_util.h"
+#include "kvm_util.h"
+#include "processor.h"
+
+#define VCPU_ID 5
+
+#define HCALL_REGION_GPA 0xc0000000ULL
+#define HCALL_REGION_SLOT 10
+
+static struct kvm_vm *vm;
+
+#define INPUTVALUE 17
+#define ARGVALUE(x) (0xdeadbeef5a5a0000UL + x)
+#define RETVALUE 0xcafef00dfbfbffffUL
+
+#define XEN_HYPERCALL_MSR 0x40000000
+
+static void guest_code(void)
+{
+ unsigned long rax = INPUTVALUE;
+ unsigned long rdi = ARGVALUE(1);
+ unsigned long rsi = ARGVALUE(2);
+ unsigned long rdx = ARGVALUE(3);
+ register unsigned long r10 __asm__("r10") = ARGVALUE(4);
+ register unsigned long r8 __asm__("r8") = ARGVALUE(5);
+ register unsigned long r9 __asm__("r9") = ARGVALUE(6);
+
+ /* First a direct invocation of 'vmcall' */
+ __asm__ __volatile__("vmcall" :
+ "=a"(rax) :
+ "a"(rax), "D"(rdi), "S"(rsi), "d"(rdx),
+ "r"(r10), "r"(r8), "r"(r9));
+ GUEST_ASSERT(rax == RETVALUE);
+
+ /* Now fill in the hypercall page */
+ __asm__ __volatile__("wrmsr" : : "c" (XEN_HYPERCALL_MSR),
+ "a" (HCALL_REGION_GPA & 0xffffffff),
+ "d" (HCALL_REGION_GPA >> 32));
+
+ /* And invoke the same hypercall that way */
+ __asm__ __volatile__("call *%1" : "=a"(rax) :
+ "r"(HCALL_REGION_GPA + INPUTVALUE * 32),
+ "a"(rax), "D"(rdi), "S"(rsi), "d"(rdx),
+ "r"(r10), "r"(r8), "r"(r9));
+ GUEST_ASSERT(rax == RETVALUE);
+
+ GUEST_DONE();
+}
+
+int main(int argc, char *argv[])
+{
+ if (!(kvm_check_cap(KVM_CAP_XEN_HVM) &
+ KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL) ) {
+ print_skip("KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL not available");
+ exit(KSFT_SKIP);
+ }
+
+ vm = vm_create_default(VCPU_ID, 0, (void *) guest_code);
+ vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid());
+
+ struct kvm_xen_hvm_config hvmc = {
+ .flags = KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL,
+ .msr = XEN_HYPERCALL_MSR,
+ };
+ vm_ioctl(vm, KVM_XEN_HVM_CONFIG, &hvmc);
+
+ /* Map a region for the hypercall page */
+ vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS,
+ HCALL_REGION_GPA, HCALL_REGION_SLOT,
+ getpagesize(), 0);
+ virt_map(vm, HCALL_REGION_GPA, HCALL_REGION_GPA, 1, 0);
+
+ for (;;) {
+ volatile struct kvm_run *run = vcpu_state(vm, VCPU_ID);
+ struct ucall uc;
+
+ vcpu_run(vm, VCPU_ID);
+
+ if (run->exit_reason == KVM_EXIT_XEN) {
+ ASSERT_EQ(run->xen.type, KVM_EXIT_XEN_HCALL);
+ ASSERT_EQ(run->xen.u.hcall.cpl, 0);
+ ASSERT_EQ(run->xen.u.hcall.longmode, 1);
+ ASSERT_EQ(run->xen.u.hcall.input, INPUTVALUE);
+ ASSERT_EQ(run->xen.u.hcall.params[0], ARGVALUE(1));
+ ASSERT_EQ(run->xen.u.hcall.params[1], ARGVALUE(2));
+ ASSERT_EQ(run->xen.u.hcall.params[2], ARGVALUE(3));
+ ASSERT_EQ(run->xen.u.hcall.params[3], ARGVALUE(4));
+ ASSERT_EQ(run->xen.u.hcall.params[4], ARGVALUE(5));
+ ASSERT_EQ(run->xen.u.hcall.params[5], ARGVALUE(6));
+ run->xen.u.hcall.result = RETVALUE;
+ continue;
+ }
+
+ TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
+ "Got exit_reason other than KVM_EXIT_IO: %u (%s)\n",
+ run->exit_reason,
+ exit_reason_str(run->exit_reason));
+
+ switch (get_ucall(vm, VCPU_ID, &uc)) {
+ case UCALL_ABORT:
+ TEST_FAIL("%s", (const char *)uc.args[0]);
+ /* NOT REACHED */
+ case UCALL_SYNC:
+ break;
+ case UCALL_DONE:
+ goto done;
+ default:
+ TEST_FAIL("Unknown ucall 0x%lx.", uc.cmd);
+ }
+ }
+done:
+ kvm_vm_free(vm);
+ return 0;
+}
