On Fri, Aug 19, 2022, Vishal Annapurve wrote:
> +/*
> + * Execute KVM hypercall to change memory access type for a given gpa range.
> + *
> + * Input Args:
> + * type - memory conversion type TO_SHARED/TO_PRIVATE
> + * gpa - starting gpa address
> + * size - size of the range starting from gpa for which memory access needs
> + * to be changed
> + *
> + * Output Args: None
> + *
> + * Return: None
> + *
> + * Function called by guest logic in selftests to update the memory access type
> + * for a given gpa range. This API is useful in exercising implicit conversion
> + * path.
> + */
> +void guest_update_mem_access(enum mem_conversion_type type, uint64_t gpa,
> + uint64_t size)
Provide wrappers to self-document what's going on, then the massive block comments
go away. And the guts of this and guest_update_mem_map() are nearly identical.
Hmm, and we probably want to make it possible to do negative testing.
Then the one-off enums for TO_PRIVATE and whatnot go way too.
> +{
> + int ret = kvm_hypercall(KVM_HC_MAP_GPA_RANGE, gpa, size >> MIN_PAGE_SHIFT,
Needs an assert that @size is page aligned. And since these are x86-64 specific,
just use PAGE_SHIFT. Huh, IS_ALIGNED() doesn't exist in selftests. That should
be added, either by pulling in align.h or by adding the generic macros to
kvm_util_base.h.
And then x86-64's processor.h can defined IS_PAGE_ALIGNED().
E.g.
static inline void __kvm_hypercall_map_gpa_range(uint64_t gpa, uint64_t size,
uint64_t flags)
{
return = kvm_hypercall(KVM_HC_MAP_GPA_RANGE, gpa, size >> PAGE_SHIFT, flags, 0);
}
static inline void kvm_hypercall_map_gpa_range(uint64_t gpa, uint64_t size,
uint64_t flags)
{
int ret;
GUEST_ASSERT_2(IS_PAGE_ALIGNED(gpa) && IS_PAGE_ALIGNED(size), gpa, size);
ret = __kvm_hypercall_map_gpa_range(gpa, size, flags);
GUEST_ASSERT_1(!ret, ret);
}
static inline kvm_hypercall_map_shared(uint64_t gpa, uint64_t size)
{
kvm_hypercall_map_gpa_range(gpa, size, KVM_CLR_GPA_RANGE_ENC_ACCESS);
}
static inline kvm_hypercall_map_private(uint64_t gpa, uint64_t size)
{
kvm_hypercall_map_gpa_range(gpa, size, KVM_MARK_GPA_RANGE_ENC_ACCESS);
}
> +static void handle_vm_exit_map_gpa_hypercall(struct kvm_vm *vm,
> + volatile struct kvm_run *run)
Pass in @vcpu, not a vm+run.
> +{
> + uint64_t gpa, npages, attrs, size;
> +
> + TEST_ASSERT(run->hypercall.nr == KVM_HC_MAP_GPA_RANGE,
> + "Unhandled Hypercall %lld\n", run->hypercall.nr);
> + gpa = run->hypercall.args[0];
> + npages = run->hypercall.args[1];
> + size = npages << MIN_PAGE_SHIFT;
> + attrs = run->hypercall.args[2];
> + pr_info("Explicit conversion off 0x%lx size 0x%lx to %s\n", gpa, size,
> + (attrs & KVM_MAP_GPA_RANGE_ENCRYPTED) ? "private" : "shared");
> +
> + if (attrs & KVM_MAP_GPA_RANGE_ENCRYPTED)
> + vm_update_private_mem(vm, gpa, size, ALLOCATE_MEM);
> + else
> + vm_update_private_mem(vm, gpa, size, UNBACK_MEM);
> +
> + run->hypercall.ret = 0;
> +}
> +
> +static void handle_vm_exit_memory_error(struct kvm_vm *vm, volatile struct kvm_run *run)
Same here, take a @vcpu.
