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Commit 14c47b75 authored by Andrew Jones's avatar Andrew Jones Committed by Paolo Bonzini
Browse files

kvm: selftests: introduce ucall 



Rework the guest exit to userspace code to generalize the concept
into what it is, a "hypercall to userspace", and provide two
implementations of it: the PortIO version currently used, but only
useable by x86, and an MMIO version that other architectures (except
s390) can use.

Signed-off-by: default avatarAndrew Jones <drjones@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 6c930268

tools/testing/selftests/kvm/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -3,7 +3,7 @@ all: 
top_srcdir = ../../../../

UNAME_M := $(shell uname -m)



LIBKVM = lib/assert.c lib/elf.c lib/io.c lib/kvm_util.c lib/sparsebit.c

LIBKVM = lib/assert.c lib/elf.c lib/io.c lib/kvm_util.c lib/ucall.c lib/sparsebit.c

LIBKVM_x86_64 = lib/x86.c lib/vmx.c



TEST_GEN_PROGS_x86_64 = platform_info_test

tools/testing/selftests/kvm/cr4_cpuid_sync_test.c

+6 −6
Original line number Diff line number Diff line
@@ -67,6 +67,7 @@ int main(int argc, char *argv[]) 
	struct kvm_vm *vm;

	struct kvm_sregs sregs;

	struct kvm_cpuid_entry2 *entry;

	struct ucall uc;

	int rc;



	entry = kvm_get_supported_cpuid_entry(1);
@@ -87,21 +88,20 @@ int main(int argc, char *argv[]) 
		rc = _vcpu_run(vm, VCPU_ID);



		if (run->exit_reason == KVM_EXIT_IO) {

			switch (run->io.port) {

			case GUEST_PORT_SYNC:

			switch (get_ucall(vm, VCPU_ID, &uc)) {

			case UCALL_SYNC:

				/* emulate hypervisor clearing CR4.OSXSAVE */

				vcpu_sregs_get(vm, VCPU_ID, &sregs);

				sregs.cr4 &= ~X86_CR4_OSXSAVE;

				vcpu_sregs_set(vm, VCPU_ID, &sregs);

				break;

			case GUEST_PORT_ABORT:

			case UCALL_ABORT:

				TEST_ASSERT(false, "Guest CR4 bit (OSXSAVE) unsynchronized with CPUID bit.");

				break;

			case GUEST_PORT_DONE:

			case UCALL_DONE:

				goto done;

			default:

				TEST_ASSERT(false, "Unknown port 0x%x.",

					    run->io.port);

				TEST_ASSERT(false, "Unknown ucall 0x%x.", uc.cmd);

			}

		}

	}

tools/testing/selftests/kvm/dirty_log_test.c

+2 −3
Original line number Diff line number Diff line
@@ -110,7 +110,7 @@ void *vcpu_worker(void *data) 
	uint64_t loops, *guest_array, pages_count = 0;

	struct kvm_vm *vm = data;

	struct kvm_run *run;

	struct guest_args args;

	struct ucall uc;



	run = vcpu_state(vm, VCPU_ID);
@@ -124,9 +124,8 @@ void *vcpu_worker(void *data) 
	while (!READ_ONCE(host_quit)) {

		/* Let the guest to dirty these random pages */

		ret = _vcpu_run(vm, VCPU_ID);

		guest_args_read(vm, VCPU_ID, &args);

		if (run->exit_reason == KVM_EXIT_IO &&

		    args.port == GUEST_PORT_SYNC) {

		    get_ucall(vm, VCPU_ID, &uc) == UCALL_SYNC) {

			pages_count += TEST_PAGES_PER_LOOP;

			generate_random_array(guest_array, TEST_PAGES_PER_LOOP);

		} else {

tools/testing/selftests/kvm/include/kvm_util.h

+41 −35
Original line number Diff line number Diff line
@@ -152,43 +152,49 @@ allocate_kvm_dirty_log(struct kvm_userspace_memory_region *region); 


int vm_create_device(struct kvm_vm *vm, struct kvm_create_device *cd);



#define GUEST_PORT_SYNC         0x1000

#define GUEST_PORT_ABORT        0x1001

#define GUEST_PORT_DONE         0x1002

#define sync_global_to_guest(vm, g) ({				\

	typeof(g) *_p = addr_gva2hva(vm, (vm_vaddr_t)&(g));	\

	memcpy(_p, &(g), sizeof(g));				\

})



#define sync_global_from_guest(vm, g) ({			\

	typeof(g) *_p = addr_gva2hva(vm, (vm_vaddr_t)&(g));	\

	memcpy(&(g), _p, sizeof(g));				\

})



/* ucall implementation types */

typedef enum {

	UCALL_PIO,

	UCALL_MMIO,

} ucall_type_t;



/* Common ucalls */

enum {

	UCALL_NONE,

	UCALL_SYNC,

	UCALL_ABORT,

	UCALL_DONE,

};



static inline void __exit_to_l0(uint16_t port, uint64_t arg0, uint64_t arg1)

{

	__asm__ __volatile__("in %[port], %%al"

			     :

			     : [port]"d"(port), "D"(arg0), "S"(arg1)

			     : "rax");

}

#define UCALL_MAX_ARGS 6



/*

 * Allows to pass three arguments to the host: port is 16bit wide,

 * arg0 & arg1 are 64bit wide

 */

#define GUEST_SYNC_ARGS(_port, _arg0, _arg1) \

	__exit_to_l0(_port, (uint64_t) (_arg0), (uint64_t) (_arg1))

struct ucall {

	uint64_t cmd;

	uint64_t args[UCALL_MAX_ARGS];

};



void ucall_init(struct kvm_vm *vm, ucall_type_t type, void *arg);

void ucall_uninit(struct kvm_vm *vm);

void ucall(uint64_t cmd, int nargs, ...);

uint64_t get_ucall(struct kvm_vm *vm, uint32_t vcpu_id, struct ucall *uc);



#define GUEST_SYNC(stage)	ucall(UCALL_SYNC, 2, "hello", stage)

#define GUEST_DONE()		ucall(UCALL_DONE, 0)

#define GUEST_ASSERT(_condition) do {			\

	if (!(_condition))				\

			GUEST_SYNC_ARGS(GUEST_PORT_ABORT,	\

		ucall(UCALL_ABORT, 2,			\

			"Failed guest assert: "		\

			#_condition, __LINE__);		\

} while (0)



#define GUEST_SYNC(stage)  GUEST_SYNC_ARGS(GUEST_PORT_SYNC, "hello", stage)



#define GUEST_DONE()  GUEST_SYNC_ARGS(GUEST_PORT_DONE, 0, 0)



struct guest_args {

	uint64_t arg0;

	uint64_t arg1;

	uint16_t port;

} __attribute__ ((packed));



void guest_args_read(struct kvm_vm *vm, uint32_t vcpu_id,

		     struct guest_args *args);



#endif /* SELFTEST_KVM_UTIL_H */

tools/testing/selftests/kvm/lib/kvm_util.c

+1 −14
Original line number Diff line number Diff line
@@ -133,6 +133,7 @@ struct kvm_vm *vm_create(enum vm_guest_mode mode, uint64_t phy_pages, int perm) 
	case VM_MODE_FLAT48PG:

		vm->page_size = 0x1000;

		vm->page_shift = 12;

		vm->va_bits = 48;



		/* Limit to 48-bit canonical virtual addresses. */

		vm->vpages_valid = sparsebit_alloc();
@@ -1669,17 +1670,3 @@ void *addr_gva2hva(struct kvm_vm *vm, vm_vaddr_t gva) 
{

	return addr_gpa2hva(vm, addr_gva2gpa(vm, gva));

}
 


void guest_args_read(struct kvm_vm *vm, uint32_t vcpu_id,

		     struct guest_args *args)

{

	struct kvm_run *run = vcpu_state(vm, vcpu_id);

	struct kvm_regs regs;



	memset(&regs, 0, sizeof(regs));

	vcpu_regs_get(vm, vcpu_id, &regs);



	args->port = run->io.port;

	args->arg0 = regs.rdi;

	args->arg1 = regs.rsi;

}