From: Paolo Bonzini <pbonzini@redhat.com>
To: David Woodhouse <dwmw2@infradead.org>, kvm@vger.kernel.org
Cc: Ankur Arora <ankur.a.arora@oracle.com>,
Joao Martins <joao.m.martins@oracle.com>,
Boris Ostrovsky <boris.ostrovsky@oracle.com>,
Sean Christopherson <seanjc@google.com>,
graf@amazon.com, iaslan@amazon.de, pdurrant@amazon.com,
aagch@amazon.com, fandree@amazon.com, hch@infradead.org
Subject: Re: [PATCH v5 02/16] KVM: x86/xen: intercept xen hypercalls if enabled
Date: Thu, 28 Jan 2021 13:21:14 +0100 [thread overview]
Message-ID: <5f710184-b32d-3882-e9cd-6de5f1175f6c@redhat.com> (raw)
In-Reply-To: <20210111195725.4601-3-dwmw2@infradead.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;
> +}
>
next prev parent reply other threads:[~2021-01-28 12:24 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-11 19:57 [PATCH v5 00/16] KVM: Add minimal support for Xen HVM guests David Woodhouse
2021-01-11 19:57 ` [PATCH v5 01/16] KVM: x86/xen: fix Xen hypercall page msr handling David Woodhouse
2021-01-11 19:57 ` [PATCH v5 02/16] KVM: x86/xen: intercept xen hypercalls if enabled David Woodhouse
2021-01-11 23:42 ` kernel test robot
2021-01-28 12:21 ` Paolo Bonzini [this message]
2021-01-11 19:57 ` [PATCH v5 03/16] KVM: x86/xen: Fix coexistence of Xen and Hyper-V hypercalls David Woodhouse
2021-01-11 19:57 ` [PATCH v5 04/16] KVM: x86/xen: add KVM_XEN_HVM_SET_ATTR/KVM_XEN_HVM_GET_ATTR David Woodhouse
2021-01-11 19:57 ` [PATCH v5 05/16] KVM: x86/xen: latch long_mode when hypercall page is set up David Woodhouse
2021-01-11 19:57 ` [PATCH v5 06/16] KVM: x86/xen: add definitions of compat_shared_info, compat_vcpu_info David Woodhouse
2021-01-11 19:57 ` [PATCH v5 07/16] KVM: x86/xen: register shared_info page David Woodhouse
2021-01-11 19:57 ` [PATCH v5 08/16] xen: add wc_sec_hi to struct shared_info David Woodhouse
2021-01-11 19:57 ` [PATCH v5 09/16] KVM: x86/xen: update wallclock region David Woodhouse
2021-01-11 19:57 ` [PATCH v5 10/16] KVM: x86/xen: register vcpu info David Woodhouse
2021-01-11 19:57 ` [PATCH v5 11/16] KVM: x86/xen: setup pvclock updates David Woodhouse
2021-01-11 19:57 ` [PATCH v5 12/16] KVM: x86/xen: register vcpu time info region David Woodhouse
2021-01-11 19:57 ` [PATCH v5 13/16] KVM: x86/xen: register runstate info David Woodhouse
2021-01-28 12:15 ` Paolo Bonzini
2021-01-11 19:57 ` [PATCH v5 14/16] KVM: x86: declare Xen HVM shared info capability and add test case David Woodhouse
2021-01-11 19:57 ` [PATCH v5 15/16] KVM: Add documentation for Xen hypercall and shared_info updates David Woodhouse
2021-01-28 12:18 ` Paolo Bonzini
2021-01-28 16:49 ` David Woodhouse
2021-01-28 17:06 ` Paolo Bonzini
[not found] ` <f9b2b4e613ea4e6dd1f253f5092254d121c93c07.camel@infradead.org>
2021-01-29 7:59 ` Paolo Bonzini
2021-01-11 19:57 ` [PATCH v5 16/16] KVM: x86/xen: Add event channel interrupt vector upcall David Woodhouse
2021-01-28 12:43 ` Paolo Bonzini
2021-01-28 15:35 ` David Woodhouse
2021-01-28 17:01 ` Paolo Bonzini
2021-01-29 17:33 ` David Woodhouse
2021-01-29 19:19 ` Paolo Bonzini
2021-01-30 13:01 ` David Woodhouse
2021-01-21 11:56 ` [PATCH v5 17/16] KVM: x86/xen: Fix initialisation of gfn caches for Xen shared pages David Woodhouse
2021-01-28 12:45 ` [PATCH v5 00/16] KVM: Add minimal support for Xen HVM guests Paolo Bonzini
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=5f710184-b32d-3882-e9cd-6de5f1175f6c@redhat.com \
--to=pbonzini@redhat.com \
--cc=aagch@amazon.com \
--cc=ankur.a.arora@oracle.com \
--cc=boris.ostrovsky@oracle.com \
--cc=dwmw2@infradead.org \
--cc=fandree@amazon.com \
--cc=graf@amazon.com \
--cc=hch@infradead.org \
--cc=iaslan@amazon.de \
--cc=joao.m.martins@oracle.com \
--cc=kvm@vger.kernel.org \
--cc=pdurrant@amazon.com \
--cc=seanjc@google.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).