Re: [PATCH v2 1/2] KVM: arm64: Filter out invalid core register IDs in KVM_GET_REG_LIST

[Andrew Jones <drjones@xxxxxxxxxx>]

Hi Dave,

The below looks like a nice kvm selftest. Care to fit it into that
framework (tools/testing/selftests/kvm/) and post it?

Thanks,
drew

> [1]
> 
> #include <assert.h>
> #include <errno.h>
> #include <limits.h>
> #include <stddef.h>
> #include <stdio.h>
> #include <stdlib.h>
> #include <stdint.h>
> #include <string.h>
> #include <fcntl.h>
> #include <sys/ioctl.h>
> #include <linux/kvm.h>
> 
> #define KVM_PATH "/dev/kvm"
> 
> #define ARRAY_SIZE(array) (sizeof (array) / sizeof *(array))
> 
> static int get_reg_list(int vcpu, struct kvm_reg_list **pregs, size_t *psize)
> {
> 	struct kvm_reg_list *regs = *pregs;
> 	size_t num_needed = 0;
> 	const size_t reg_offset = (char *)&regs->reg - (char *)regs;
> 
> 	while (1) {
> 		size_t size_needed = num_needed * sizeof regs->reg[0]
> 					+ reg_offset;
> 		if (size_needed > *psize) {
> 			regs = realloc(regs, size_needed);
> 			if (!regs)
> 				goto nomem;
> 
> 			*pregs = regs;
> 			*psize = size_needed;
> 		}
> 
> 		regs->n = (*psize - reg_offset) / sizeof regs->reg[0];
> 		if (!ioctl(vcpu, KVM_GET_REG_LIST, regs))
> 			break;
> 
> 		if (errno != E2BIG) {
> 			perror("KVM_GET_REG_LIST");
> 			goto error;
> 		}
> 
> 		num_needed = regs->n;
> 	}
> 
> 	return 0;	
> 
> nomem:
> 	errno = ENOMEM;
> 	perror(NULL);
> error:
> 	return -1;
> }
> 
> int main(void)
> {
> 	int fail = 0;
> 	int kvm_fd, vm, vcpu;
> 	struct kvm_vcpu_init init;
> 	size_t i;
> 	struct kvm_reg_list *regs = NULL;
> 	size_t regs_size = 0;
> 	uint64_t regdata[2];
> 	struct kvm_one_reg reg;
> 
> 	kvm_fd = open(KVM_PATH, O_RDWR);
> 	if (kvm_fd == -1) {
> 		perror(KVM_PATH);
> 		goto error;
> 	}
> 
> 	vm = ioctl(kvm_fd, KVM_CREATE_VM, 0);
> 	if (vm == -1) {
> 		perror("KVM_CREATE_VM");
> 		goto error;
> 	}
> 
> 	if (ioctl(vm, KVM_ARM_PREFERRED_TARGET, &init)) {
> 		perror("KVM_ARM_PREFERRED_TARGET");
> 		goto error;
> 	}
> 
> 	printf("KVM_ARM_PREFERRED_TARGET:\n"
> 	       "\ttarget = %lu\n",
> 	       (unsigned long)init.target);
> 	for (i = 0; i < ARRAY_SIZE(init.features); ++i)
> 		printf("\tfeatures[0] = 0x%.8lx\n",
> 		       (unsigned long)init.features[i]);
> 	
> 	vcpu = ioctl(vm, KVM_CREATE_VCPU, 0);
> 	if (vcpu == -1) {
> 		perror("KVM_CREATE_VCPU");
> 		goto error;
> 	}
> 
> 	if (!get_reg_list(vcpu, &regs, &regs_size)) {
> 		fputs("Strange, KVM_GET_REG_LIST succeeded before KVM_VCPU_INIT!\n",
> 		      stderr);
> 			
> 		goto error;
> 	}
> 
> 	if (ioctl(vcpu, KVM_ARM_VCPU_INIT, &init)) {
> 		perror("KVM_ARM_VCPU_INIT");
> 		goto error;
> 	}
> 
> 	if (get_reg_list(vcpu, &regs, &regs_size))
> 		goto error;
> 
> 	assert(1 <= -1ULL >> 32);
> 	assert(ULONG_MAX >= (1ULL << 32) - 1);
> 	for (i = 0; i < regs->n; ++i) {
> 		size_t size;
> 		char const *s1 = "OK", *s2 = "", *s3 = "";;
> 
> 		size = (size_t)1 << ((regs->reg[i] & KVM_REG_SIZE_MASK) >>
> 				     KVM_REG_SIZE_SHIFT);
> 		if (size < 4 || size > 16) {
> 			s1 = "BADSIZE";
> 			fail = 1;
> 		} else {
> 			memset(&reg, 0, sizeof reg);
> 
> 			reg.id = regs->reg[i];
> 			reg.addr = (__u64)&regdata;
> 			if (ioctl(vcpu, KVM_GET_ONE_REG, &reg)) {
> 				s1 = "FAIL (";
> 				s2 = strerror(errno);
> 				s3 = ")";
> 				fail = 1;
> 			}
> 		}
> 
> 		printf("\t0x%.16lx\t%s%s%s\n",
> 		       (unsigned long)reg.id, s1, s2, s3);
> 	
> 	}
> 
> 	if (ferror(stdout) || fflush(stdout))
> 		goto stdout_error;
> 	
> 	if (fail) {
> 		puts("FAIL");
> 		goto error;
> 	}
> 
> 	if (puts("\nPASS") == EOF || fclose(stdout))
> 		goto stdout_error;
> 
> 	return EXIT_SUCCESS;
> 
> stdout_error:
> 	fputs("I/O error", stderr);
> error:
> 	return EXIT_FAILURE;
> }
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