Commit 8d4e7e80 authored by David Woodhouse's avatar David Woodhouse
Browse files

KVM: x86: declare Xen HVM shared info capability and add test case 



Instead of adding a plethora of new KVM_CAP_XEN_FOO capabilities, just
add bits to the return value of KVM_CAP_XEN_HVM.

Signed-off-by: default avatarDavid Woodhouse <dwmw@amazon.co.uk>
parent 40da8ccd

arch/x86/kvm/x86.c

+2 −1
Original line number Diff line number Diff line
@@ -3769,7 +3769,8 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) 
		break;

	case KVM_CAP_XEN_HVM:

		r = KVM_XEN_HVM_CONFIG_HYPERCALL_MSR |

		    KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL;

		    KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL |

		    KVM_XEN_HVM_CONFIG_SHARED_INFO;

		break;

	case KVM_CAP_SYNC_REGS:

		r = KVM_SYNC_X86_VALID_FIELDS;

include/uapi/linux/kvm.h

+3 −0
Original line number Diff line number Diff line
@@ -1152,6 +1152,7 @@ struct kvm_x86_mce { 
#ifdef KVM_CAP_XEN_HVM

#define KVM_XEN_HVM_CONFIG_HYPERCALL_MSR	(1 << 0)

#define KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL	(1 << 1)

#define KVM_XEN_HVM_CONFIG_SHARED_INFO		(1 << 2)



struct kvm_xen_hvm_config {

	__u32 flags;
@@ -1604,6 +1605,7 @@ struct kvm_xen_hvm_attr { 
	} u;

};



/* Available with KVM_CAP_XEN_HVM / KVM_XEN_HVM_CONFIG_SHARED_INFO */

#define KVM_XEN_ATTR_TYPE_LONG_MODE		0x0

#define KVM_XEN_ATTR_TYPE_SHARED_INFO		0x1

#define KVM_XEN_ATTR_TYPE_UPCALL_VECTOR		0x2
@@ -1621,6 +1623,7 @@ struct kvm_xen_vcpu_attr { 
	} u;

};



/* Available with KVM_CAP_XEN_HVM / KVM_XEN_HVM_CONFIG_SHARED_INFO */

#define KVM_XEN_VCPU_ATTR_TYPE_VCPU_INFO	0x0

#define KVM_XEN_VCPU_ATTR_TYPE_VCPU_TIME_INFO	0x1

tools/testing/selftests/kvm/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -62,6 +62,7 @@ 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/vmx_pmu_msrs_test

TEST_GEN_PROGS_x86_64 += x86_64/xen_shinfo_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

tools/testing/selftests/kvm/x86_64/xen_shinfo_test.c

0 → 100644
+169 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0-only

/*

 * svm_vmcall_test

 *

 * Copyright © 2021 Amazon.com, Inc. or its affiliates.

 *

 * Xen shared_info / pvclock testing

 */



#include "test_util.h"

#include "kvm_util.h"

#include "processor.h"



#include <stdint.h>

#include <time.h>



#define VCPU_ID		5



#define SHINFO_REGION_GPA	0xc0000000ULL

#define SHINFO_REGION_SLOT	10

#define PAGE_SIZE		4096



#define PVTIME_ADDR	(SHINFO_REGION_GPA + PAGE_SIZE)



static struct kvm_vm *vm;



#define XEN_HYPERCALL_MSR	0x40000000



struct pvclock_vcpu_time_info {

        u32   version;

        u32   pad0;

        u64   tsc_timestamp;

        u64   system_time;

        u32   tsc_to_system_mul;

        s8    tsc_shift;

        u8    flags;

        u8    pad[2];

} __attribute__((__packed__)); /* 32 bytes */



struct pvclock_wall_clock {

        u32   version;

        u32   sec;

        u32   nsec;

} __attribute__((__packed__));



static void guest_code(void)

{

	GUEST_DONE();

}



static int cmp_timespec(struct timespec *a, struct timespec *b)

{

	if (a->tv_sec > b->tv_sec)

		return 1;

	else if (a->tv_sec < b->tv_sec)

		return -1;

	else if (a->tv_nsec > b->tv_nsec)

		return 1;

	else if (a->tv_nsec < b->tv_nsec)

		return -1;

	else

		return 0;

}



int main(int argc, char *argv[])

{

	struct timespec min_ts, max_ts, vm_ts;



	if (!(kvm_check_cap(KVM_CAP_XEN_HVM) &

	      KVM_XEN_HVM_CONFIG_SHARED_INFO) ) {

		print_skip("KVM_XEN_HVM_CONFIG_SHARED_INFO not available");

		exit(KSFT_SKIP);

	}



	clock_gettime(CLOCK_REALTIME, &min_ts);



	vm = vm_create_default(VCPU_ID, 0, (void *) guest_code);

	vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid());



	/* Map a region for the shared_info page */

	vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS,

                                    SHINFO_REGION_GPA, SHINFO_REGION_SLOT,

				    2 * getpagesize(), 0);

	virt_map(vm, SHINFO_REGION_GPA, SHINFO_REGION_GPA, 2, 0);



	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);



	struct kvm_xen_hvm_attr lm = {

		.type = KVM_XEN_ATTR_TYPE_LONG_MODE,

		.u.long_mode = 1,

	};

	vm_ioctl(vm, KVM_XEN_HVM_SET_ATTR, &lm);



	struct kvm_xen_hvm_attr ha = {

		.type = KVM_XEN_ATTR_TYPE_SHARED_INFO,

		.u.shared_info.gfn = SHINFO_REGION_GPA / PAGE_SIZE,

	};

	vm_ioctl(vm, KVM_XEN_HVM_SET_ATTR, &ha);



	struct kvm_xen_vcpu_attr vi = {

		.type = KVM_XEN_VCPU_ATTR_TYPE_VCPU_INFO,

		.u.gpa = SHINFO_REGION_GPA + 40,

	};

	vcpu_ioctl(vm, VCPU_ID, KVM_XEN_VCPU_SET_ATTR, &vi);



	struct kvm_xen_vcpu_attr pvclock = {

		.type = KVM_XEN_VCPU_ATTR_TYPE_VCPU_TIME_INFO,

		.u.gpa = PVTIME_ADDR,

	};

	vcpu_ioctl(vm, VCPU_ID, KVM_XEN_VCPU_SET_ATTR, &pvclock);



	for (;;) {

		volatile struct kvm_run *run = vcpu_state(vm, VCPU_ID);

		struct ucall uc;



		vcpu_run(vm, VCPU_ID);



		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:

	clock_gettime(CLOCK_REALTIME, &max_ts);



	/*

	 * Just a *really* basic check that things are being put in the

	 * right place. The actual calculations are much the same for

	 * Xen as they are for the KVM variants, so no need to check.

	 */

	struct pvclock_wall_clock *wc;

	struct pvclock_vcpu_time_info *ti, *ti2;



	wc = addr_gva2hva(vm, SHINFO_REGION_GPA + 0xc00);

	ti = addr_gva2hva(vm, SHINFO_REGION_GPA + 0x40 + 0x20);

	ti2 = addr_gva2hva(vm, PVTIME_ADDR);



	vm_ts.tv_sec = wc->sec;

	vm_ts.tv_nsec = wc->nsec;

        TEST_ASSERT(wc->version && !(wc->version & 1),

		    "Bad wallclock version %x", wc->version);

	TEST_ASSERT(cmp_timespec(&min_ts, &vm_ts) <= 0, "VM time too old");

	TEST_ASSERT(cmp_timespec(&max_ts, &vm_ts) >= 0, "VM time too new");



	TEST_ASSERT(ti->version && !(ti->version & 1),

		    "Bad time_info version %x", ti->version);

	TEST_ASSERT(ti2->version && !(ti2->version & 1),

		    "Bad time_info version %x", ti->version);



	kvm_vm_free(vm);

	return 0;

}