Commit ae16b0ab authored by Christoph Schlameuss's avatar Christoph Schlameuss Committed by Janosch Frank
Browse files

KVM: s390: selftests: Add uc_map_unmap VM test case 



Add a test case verifying basic running and interaction of ucontrol VMs.
Fill the segment and page tables for allocated memory and map memory on
first access.

* uc_map_unmap
  Store and load data to mapped and unmapped memory and use pic segment
  translation handling to map memory on access.

Signed-off-by: default avatarChristoph Schlameuss <schlameuss@linux.ibm.com>
Reviewed-by: default avatarJanosch Frank <frankja@linux.ibm.com>
Link:
https://lore.kernel.org/r/20241107141024.238916-2-schlameuss@linux.ibm.com


[frankja@linux.ibm.com: Fixed patch prefix]
Signed-off-by: default avatarJanosch Frank <frankja@linux.ibm.com>
Message-ID: <20241107141024.238916-2-schlameuss@linux.ibm.com>
parent 75ec613e

tools/testing/selftests/kvm/s390x/ucontrol_test.c

+144 −1
Original line number Diff line number Diff line
@@ -16,7 +16,11 @@ 
#include <linux/capability.h>

#include <linux/sizes.h>



#define PGM_SEGMENT_TRANSLATION 0x10



#define VM_MEM_SIZE (4 * SZ_1M)

#define VM_MEM_EXT_SIZE (2 * SZ_1M)

#define VM_MEM_MAX_M ((VM_MEM_SIZE + VM_MEM_EXT_SIZE) / SZ_1M)



/* so directly declare capget to check caps without libcap */

int capget(cap_user_header_t header, cap_user_data_t data);
@@ -58,6 +62,23 @@ asm("test_gprs_asm:\n" 
	"	j	0b\n"

);



/* Test program manipulating memory */

extern char test_mem_asm[];

asm("test_mem_asm:\n"

	"xgr	%r0, %r0\n"



	"0:\n"

	"	ahi	%r0,1\n"

	"	st	%r1,0(%r5,%r6)\n"



	"	xgr	%r1,%r1\n"

	"	l	%r1,0(%r5,%r6)\n"

	"	ahi	%r0,1\n"

	"	diag	0,0,0x44\n"



	"	j	0b\n"

);



FIXTURE(uc_kvm)

{

	struct kvm_s390_sie_block *sie_block;
@@ -67,6 +88,7 @@ FIXTURE(uc_kvm) 
	uintptr_t base_hva;

	uintptr_t code_hva;

	int kvm_run_size;

	vm_paddr_t pgd;

	void *vm_mem;

	int vcpu_fd;

	int kvm_fd;
@@ -116,7 +138,7 @@ FIXTURE_SETUP(uc_kvm) 
	self->base_gpa = 0;

	self->code_gpa = self->base_gpa + (3 * SZ_1M);



	self->vm_mem = aligned_alloc(SZ_1M, VM_MEM_SIZE);

	self->vm_mem = aligned_alloc(SZ_1M, VM_MEM_MAX_M * SZ_1M);

	ASSERT_NE(NULL, self->vm_mem) TH_LOG("malloc failed %u", errno);

	self->base_hva = (uintptr_t)self->vm_mem;

	self->code_hva = self->base_hva - self->base_gpa + self->code_gpa;
@@ -222,6 +244,60 @@ TEST(uc_cap_hpage) 
	close(kvm_fd);

}



/* calculate host virtual addr from guest physical addr */

static void *gpa2hva(FIXTURE_DATA(uc_kvm) *self, u64 gpa)

{

	return (void *)(self->base_hva - self->base_gpa + gpa);

}



/* map / make additional memory available */

static int uc_map_ext(FIXTURE_DATA(uc_kvm) *self, u64 vcpu_addr, u64 length)

{

	struct kvm_s390_ucas_mapping map = {

		.user_addr = (u64)gpa2hva(self, vcpu_addr),

		.vcpu_addr = vcpu_addr,

		.length = length,

	};

	pr_info("ucas map %p %p 0x%llx",

		(void *)map.user_addr, (void *)map.vcpu_addr, map.length);

	return ioctl(self->vcpu_fd, KVM_S390_UCAS_MAP, &map);

}



/* unmap previously mapped memory */

static int uc_unmap_ext(FIXTURE_DATA(uc_kvm) *self, u64 vcpu_addr, u64 length)

{

	struct kvm_s390_ucas_mapping map = {

		.user_addr = (u64)gpa2hva(self, vcpu_addr),

		.vcpu_addr = vcpu_addr,

		.length = length,

	};

	pr_info("ucas unmap %p %p 0x%llx",

		(void *)map.user_addr, (void *)map.vcpu_addr, map.length);

	return ioctl(self->vcpu_fd, KVM_S390_UCAS_UNMAP, &map);

}



/* handle ucontrol exit by mapping the accessed segment */

static void uc_handle_exit_ucontrol(FIXTURE_DATA(uc_kvm) *self)

{

	struct kvm_run *run = self->run;

	u64 seg_addr;

	int rc;



	TEST_ASSERT_EQ(KVM_EXIT_S390_UCONTROL, run->exit_reason);

	switch (run->s390_ucontrol.pgm_code) {

	case PGM_SEGMENT_TRANSLATION:

		seg_addr = run->s390_ucontrol.trans_exc_code & ~(SZ_1M - 1);

		pr_info("ucontrol pic segment translation 0x%llx, mapping segment 0x%lx\n",

			run->s390_ucontrol.trans_exc_code, seg_addr);

		/* map / make additional memory available */

		rc = uc_map_ext(self, seg_addr, SZ_1M);

		TEST_ASSERT_EQ(0, rc);

		break;

	default:

		TEST_FAIL("UNEXPECTED PGM CODE %d", run->s390_ucontrol.pgm_code);

	}

}



/* verify SIEIC exit

 * * fail on codes not expected in the test cases

 */
@@ -255,6 +331,12 @@ static bool uc_handle_exit(FIXTURE_DATA(uc_kvm) * self) 
	struct kvm_run *run = self->run;



	switch (run->exit_reason) {

	case KVM_EXIT_S390_UCONTROL:

		/** check program interruption code

		 * handle page fault --> ucas map

		 */

		uc_handle_exit_ucontrol(self);

		break;

	case KVM_EXIT_S390_SIEIC:

		return uc_handle_sieic(self);

	default:
@@ -286,6 +368,67 @@ static void uc_assert_diag44(FIXTURE_DATA(uc_kvm) * self) 
	TEST_ASSERT_EQ(0x440000, sie_block->ipb);

}



TEST_F(uc_kvm, uc_map_unmap)

{

	struct kvm_sync_regs *sync_regs = &self->run->s.regs;

	struct kvm_run *run = self->run;

	const u64 disp = 1;

	int rc;



	/* copy test_mem_asm to code_hva / code_gpa */

	TH_LOG("copy code %p to vm mapped memory %p / %p",

	       &test_mem_asm, (void *)self->code_hva, (void *)self->code_gpa);

	memcpy((void *)self->code_hva, &test_mem_asm, PAGE_SIZE);



	/* DAT disabled + 64 bit mode */

	run->psw_mask = 0x0000000180000000ULL;

	run->psw_addr = self->code_gpa;



	/* set register content for test_mem_asm to access not mapped memory*/

	sync_regs->gprs[1] = 0x55;

	sync_regs->gprs[5] = self->base_gpa;

	sync_regs->gprs[6] = VM_MEM_SIZE + disp;

	run->kvm_dirty_regs |= KVM_SYNC_GPRS;



	/* run and expect to fail with ucontrol pic segment translation */

	ASSERT_EQ(0, uc_run_once(self));

	ASSERT_EQ(1, sync_regs->gprs[0]);

	ASSERT_EQ(KVM_EXIT_S390_UCONTROL, run->exit_reason);



	ASSERT_EQ(PGM_SEGMENT_TRANSLATION, run->s390_ucontrol.pgm_code);

	ASSERT_EQ(self->base_gpa + VM_MEM_SIZE, run->s390_ucontrol.trans_exc_code);



	/* fail to map memory with not segment aligned address */

	rc = uc_map_ext(self, self->base_gpa + VM_MEM_SIZE + disp, VM_MEM_EXT_SIZE);

	ASSERT_GT(0, rc)

		TH_LOG("ucas map for non segment address should fail but didn't; "

		       "result %d not expected, %s", rc, strerror(errno));



	/* map / make additional memory available */

	rc = uc_map_ext(self, self->base_gpa + VM_MEM_SIZE, VM_MEM_EXT_SIZE);

	ASSERT_EQ(0, rc)

		TH_LOG("ucas map result %d not expected, %s", rc, strerror(errno));

	ASSERT_EQ(0, uc_run_once(self));

	ASSERT_EQ(false, uc_handle_exit(self));

	uc_assert_diag44(self);



	/* assert registers and memory are in expected state */

	ASSERT_EQ(2, sync_regs->gprs[0]);

	ASSERT_EQ(0x55, sync_regs->gprs[1]);

	ASSERT_EQ(0x55, *(u32 *)gpa2hva(self, self->base_gpa + VM_MEM_SIZE + disp));



	/* unmap and run loop again */

	rc = uc_unmap_ext(self, self->base_gpa + VM_MEM_SIZE, VM_MEM_EXT_SIZE);

	ASSERT_EQ(0, rc)

		TH_LOG("ucas unmap result %d not expected, %s", rc, strerror(errno));

	ASSERT_EQ(0, uc_run_once(self));

	ASSERT_EQ(3, sync_regs->gprs[0]);

	ASSERT_EQ(KVM_EXIT_S390_UCONTROL, run->exit_reason);

	ASSERT_EQ(PGM_SEGMENT_TRANSLATION, run->s390_ucontrol.pgm_code);

	/* handle ucontrol exit and remap memory after previous map and unmap */

	ASSERT_EQ(true, uc_handle_exit(self));

}



TEST_F(uc_kvm, uc_gprs)

{

	struct kvm_sync_regs *sync_regs = &self->run->s.regs;