| Message ID | 20210111195725.4601-3-dwmw2@infradead.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: Add minimal support for Xen HVM guests | expand |
Hi David,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on v5.11-rc3]
[also build test WARNING on next-20210111]
[cannot apply to kvm/linux-next xen-tip/linux-next vhost/linux-next]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]
url: https://github.com/0day-ci/linux/commits/David-Woodhouse/KVM-Add-minimal-support-for-Xen-HVM-guests/20210112-040054
base: 7c53f6b671f4aba70ff15e1b05148b10d58c2837
config: x86_64-randconfig-s022-20210111 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-15) 9.3.0
reproduce:
# apt-get install sparse
# sparse version: v0.6.3-208-g46a52ca4-dirty
# https://github.com/0day-ci/linux/commit/9e109a13c92b207e4edbaf4b8ccb22a32ffcb587
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review David-Woodhouse/KVM-Add-minimal-support-for-Xen-HVM-guests/20210112-040054
git checkout 9e109a13c92b207e4edbaf4b8ccb22a32ffcb587
# save the attached .config to linux build tree
make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' ARCH=x86_64
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
"sparse warnings: (new ones prefixed by >>)"
>> arch/x86/kvm/xen.c:67:46: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected void const [noderef] __user * @@ got unsigned char [usertype] * @@
arch/x86/kvm/xen.c:67:46: sparse: expected void const [noderef] __user *
arch/x86/kvm/xen.c:67:46: sparse: got unsigned char [usertype] *
vim +67 arch/x86/kvm/xen.c
17
18 int kvm_xen_hvm_config(struct kvm_vcpu *vcpu, u64 data)
19 {
20 struct kvm *kvm = vcpu->kvm;
21 u32 page_num = data & ~PAGE_MASK;
22 u64 page_addr = data & PAGE_MASK;
23
24 /*
25 * If Xen hypercall intercept is enabled, fill the hypercall
26 * page with VMCALL/VMMCALL instructions since that's what
27 * we catch. Else the VMM has provided the hypercall pages
28 * with instructions of its own choosing, so use those.
29 */
30 if (kvm_xen_hypercall_enabled(kvm)) {
31 u8 instructions[32];
32 int i;
33
34 if (page_num)
35 return 1;
36
37 /* mov imm32, %eax */
38 instructions[0] = 0xb8;
39
40 /* vmcall / vmmcall */
41 kvm_x86_ops.patch_hypercall(vcpu, instructions + 5);
42
43 /* ret */
44 instructions[8] = 0xc3;
45
46 /* int3 to pad */
47 memset(instructions + 9, 0xcc, sizeof(instructions) - 9);
48
49 for (i = 0; i < PAGE_SIZE / sizeof(instructions); i++) {
50 *(u32 *)&instructions[1] = i;
51 if (kvm_vcpu_write_guest(vcpu,
52 page_addr + (i * sizeof(instructions)),
53 instructions, sizeof(instructions)))
54 return 1;
55 }
56 } else {
57 int lm = is_long_mode(vcpu);
58 u8 *blob_addr = lm ? (u8 *)(long)kvm->arch.xen_hvm_config.blob_addr_64
59 : (u8 *)(long)kvm->arch.xen_hvm_config.blob_addr_32;
60 u8 blob_size = lm ? kvm->arch.xen_hvm_config.blob_size_64
61 : kvm->arch.xen_hvm_config.blob_size_32;
62 u8 *page;
63
64 if (page_num >= blob_size)
65 return 1;
66
> 67 page = memdup_user(blob_addr + (page_num * PAGE_SIZE), PAGE_SIZE);
68 if (IS_ERR(page))
69 return PTR_ERR(page);
70
71 if (kvm_vcpu_write_guest(vcpu, page_addr, page, PAGE_SIZE)) {
72 kfree(page);
73 return 1;
74 }
75 }
76 return 0;
77 }
78
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
On 11/01/21 20:57, David Woodhouse wrote: > + } 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; I know this is preexisting, but please just make those pointers "u8 __user *" to calm down the static checker. Paolo > + 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 374c67875cdb..9eee81bcd0e0 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 > > @@ -252,6 +266,7 @@ struct kvm_hyperv_exit { > #define KVM_EXIT_X86_WRMSR 30 > #define KVM_EXIT_DIRTY_RING_FULL 31 > #define KVM_EXIT_AP_RESET_HOLD 32 > +#define KVM_EXIT_XEN 33 > > /* For KVM_EXIT_INTERNAL_ERROR */ > /* Emulate instruction failed. */ > @@ -428,6 +443,8 @@ 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]; > }; > @@ -1131,6 +1148,9 @@ struct kvm_x86_mce { > #endif > > #ifdef KVM_CAP_XEN_HVM > +#define KVM_XEN_HVM_CONFIG_HYPERCALL_MSR (1 << 0) > +#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 fe41c6a0fa67..44a4128b4061 100644 > --- a/tools/testing/selftests/kvm/Makefile > +++ b/tools/testing/selftests/kvm/Makefile > @@ -59,6 +59,8 @@ TEST_GEN_PROGS_x86_64 += x86_64/vmx_tsc_adjust_test > 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 fa5a90e6c6f0..d787cb802b4a 100644 > --- a/tools/testing/selftests/kvm/lib/kvm_util.c > +++ b/tools/testing/selftests/kvm/lib/kvm_util.c > @@ -1801,6 +1801,7 @@ static struct exit_reason { > {KVM_EXIT_DIRTY_RING_FULL, "DIRTY_RING_FULL"}, > {KVM_EXIT_X86_RDMSR, "RDMSR"}, > {KVM_EXIT_X86_WRMSR, "WRMSR"}, > + {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; > +} >
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 3d6616f6f6ef..cf2af8efebe8 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -520,6 +520,11 @@ struct kvm_vcpu_hv { cpumask_t tlb_flush; }; +/* Xen HVM per vcpu emulation context */ +struct kvm_vcpu_xen { + u64 hypercall_rip; +}; + struct kvm_vcpu_arch { /* * rip and regs accesses must go through @@ -718,6 +723,7 @@ struct kvm_vcpu_arch { unsigned long singlestep_rip; struct kvm_vcpu_hv hyperv; + struct kvm_vcpu_xen xen; cpumask_var_t wbinvd_dirty_mask; diff --git a/arch/x86/kvm/Makefile b/arch/x86/kvm/Makefile index 4bd14ab01323..a50041235530 100644 --- a/arch/x86/kvm/Makefile +++ b/arch/x86/kvm/Makefile @@ -14,7 +14,7 @@ kvm-y += $(KVM)/kvm_main.o $(KVM)/coalesced_mmio.o \ $(KVM)/dirty_ring.o kvm-$(CONFIG_KVM_ASYNC_PF) += $(KVM)/async_pf.o -kvm-y += x86.o emulate.o i8259.o irq.o lapic.o \ +kvm-y += x86.o emulate.o i8259.o irq.o lapic.o xen.o \ i8254.o ioapic.o irq_comm.o cpuid.o pmu.o mtrr.o \ hyperv.o debugfs.o mmu/mmu.o mmu/page_track.o \ mmu/spte.o mmu/tdp_iter.o mmu/tdp_mmu.o diff --git a/arch/x86/kvm/trace.h b/arch/x86/kvm/trace.h index 2de30c20bc26..4527d0fd2d99 100644 --- a/arch/x86/kvm/trace.h +++ b/arch/x86/kvm/trace.h @@ -92,6 +92,42 @@ TRACE_EVENT(kvm_hv_hypercall, __entry->outgpa) ); +/* + * Tracepoint for Xen hypercall. + */ +TRACE_EVENT(kvm_xen_hypercall, + TP_PROTO(unsigned long nr, unsigned long a0, unsigned long a1, + unsigned long a2, unsigned long a3, unsigned long a4, + unsigned long a5), + TP_ARGS(nr, a0, a1, a2, a3, a4, a5), + + TP_STRUCT__entry( + __field(unsigned long, nr) + __field(unsigned long, a0) + __field(unsigned long, a1) + __field(unsigned long, a2) + __field(unsigned long, a3) + __field(unsigned long, a4) + __field(unsigned long, a5) + ), + + TP_fast_assign( + __entry->nr = nr; + __entry->a0 = a0; + __entry->a1 = a1; + __entry->a2 = a2; + __entry->a3 = a3; + __entry->a4 = a4; + __entry->a4 = a5; + ), + + TP_printk("nr 0x%lx a0 0x%lx a1 0x%lx a2 0x%lx a3 0x%lx a4 0x%lx a5 %lx", + __entry->nr, __entry->a0, __entry->a1, __entry->a2, + __entry->a3, __entry->a4, __entry->a5) +); + + + /* * Tracepoint for PIO. */ diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index c0c3a904080f..4e6b8c4d7824 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -29,6 +29,7 @@ #include "pmu.h" #include "hyperv.h" #include "lapic.h" +#include "xen.h" #include <linux/clocksource.h> #include <linux/interrupt.h> @@ -2848,32 +2849,6 @@ static int set_msr_mce(struct kvm_vcpu *vcpu, struct msr_data *msr_info) return 0; } -static int xen_hvm_config(struct kvm_vcpu *vcpu, u64 data) -{ - struct kvm *kvm = vcpu->kvm; - 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; - u32 page_num = data & ~PAGE_MASK; - u64 page_addr = data & PAGE_MASK; - 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 inline bool kvm_pv_async_pf_enabled(struct kvm_vcpu *vcpu) { u64 mask = KVM_ASYNC_PF_ENABLED | KVM_ASYNC_PF_DELIVERY_AS_INT; @@ -3008,7 +2983,7 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info) u64 data = msr_info->data; if (msr && msr == vcpu->kvm->arch.xen_hvm_config.msr) - return xen_hvm_config(vcpu, data); + return kvm_xen_hvm_config(vcpu, data); switch (msr) { case MSR_AMD64_NB_CFG: @@ -3730,7 +3705,6 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) case KVM_CAP_PIT2: case KVM_CAP_PIT_STATE2: case KVM_CAP_SET_IDENTITY_MAP_ADDR: - case KVM_CAP_XEN_HVM: case KVM_CAP_VCPU_EVENTS: case KVM_CAP_HYPERV: case KVM_CAP_HYPERV_VAPIC: @@ -3770,6 +3744,10 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) case KVM_CAP_ENFORCE_PV_FEATURE_CPUID: r = 1; break; + case KVM_CAP_XEN_HVM: + r = KVM_XEN_HVM_CONFIG_HYPERCALL_MSR | + KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL; + break; case KVM_CAP_SYNC_REGS: r = KVM_SYNC_X86_VALID_FIELDS; break; @@ -5626,7 +5604,15 @@ long kvm_arch_vm_ioctl(struct file *filp, if (copy_from_user(&xhc, argp, sizeof(xhc))) goto out; r = -EINVAL; - if (xhc.flags) + if (xhc.flags & ~KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL) + goto out; + /* + * With hypercall interception the kernel generates its own + * hypercall page so it must not be provided. + */ + if ((xhc.flags & KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL) && + (xhc.blob_addr_32 || xhc.blob_addr_64 || + xhc.blob_size_32 || xhc.blob_size_64)) goto out; memcpy(&kvm->arch.xen_hvm_config, &xhc, sizeof(xhc)); r = 0; @@ -8102,6 +8088,9 @@ int kvm_emulate_hypercall(struct kvm_vcpu *vcpu) unsigned long nr, a0, a1, a2, a3, ret; int op_64_bit; + if (kvm_xen_hypercall_enabled(vcpu->kvm)) + return kvm_xen_hypercall(vcpu); + if (kvm_hv_hypercall_enabled(vcpu->kvm)) return kvm_hv_hypercall(vcpu); diff --git a/arch/x86/kvm/xen.c b/arch/x86/kvm/xen.c new file mode 100644 index 000000000000..b76d121a86c0 --- /dev/null +++ b/arch/x86/kvm/xen.c @@ -0,0 +1,140 @@ +// 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 + */ + +#include "x86.h" +#include "xen.h" + +#include <linux/kvm_host.h> + +#include <trace/events/kvm.h> + +#include "trace.h" + +int kvm_xen_hvm_config(struct kvm_vcpu *vcpu, u64 data) +{ + struct kvm *kvm = vcpu->kvm; + u32 page_num = data & ~PAGE_MASK; + u64 page_addr = data & PAGE_MASK; + + /* + * If Xen hypercall intercept is enabled, fill the hypercall + * page with VMCALL/VMMCALL instructions since that's what + * we catch. Else the VMM has provided the hypercall pages + * with instructions of its own choosing, so use those. + */ + if (kvm_xen_hypercall_enabled(kvm)) { + u8 instructions[32]; + int i; + + if (page_num) + return 1; + + /* mov imm32, %eax */ + instructions[0] = 0xb8; + + /* vmcall / vmmcall */ + kvm_x86_ops.patch_hypercall(vcpu, instructions + 5); + + /* ret */ + instructions[8] = 0xc3; + + /* int3 to pad */ + memset(instructions + 9, 0xcc, sizeof(instructions) - 9); + + for (i = 0; i < PAGE_SIZE / sizeof(instructions); i++) { + *(u32 *)&instructions[1] = i; + if (kvm_vcpu_write_guest(vcpu, + page_addr + (i * sizeof(instructions)), + instructions, sizeof(instructions))) + return 1; + } + } 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 374c67875cdb..9eee81bcd0e0 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 @@ -252,6 +266,7 @@ struct kvm_hyperv_exit { #define KVM_EXIT_X86_WRMSR 30 #define KVM_EXIT_DIRTY_RING_FULL 31 #define KVM_EXIT_AP_RESET_HOLD 32 +#define KVM_EXIT_XEN 33 /* For KVM_EXIT_INTERNAL_ERROR */ /* Emulate instruction failed. */ @@ -428,6 +443,8 @@ 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]; }; @@ -1131,6 +1148,9 @@ struct kvm_x86_mce { #endif #ifdef KVM_CAP_XEN_HVM +#define KVM_XEN_HVM_CONFIG_HYPERCALL_MSR (1 << 0) +#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 fe41c6a0fa67..44a4128b4061 100644 --- a/tools/testing/selftests/kvm/Makefile +++ b/tools/testing/selftests/kvm/Makefile @@ -59,6 +59,8 @@ TEST_GEN_PROGS_x86_64 += x86_64/vmx_tsc_adjust_test 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 fa5a90e6c6f0..d787cb802b4a 100644 --- a/tools/testing/selftests/kvm/lib/kvm_util.c +++ b/tools/testing/selftests/kvm/lib/kvm_util.c @@ -1801,6 +1801,7 @@ static struct exit_reason { {KVM_EXIT_DIRTY_RING_FULL, "DIRTY_RING_FULL"}, {KVM_EXIT_X86_RDMSR, "RDMSR"}, {KVM_EXIT_X86_WRMSR, "WRMSR"}, + {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; +}