[PATCH 26/34] KVM: selftests: Add helpers to do KVM_HC_MAP_GPA_RANGE hypercalls (x86)

[Fuad Tabba]

On Sun, Nov 5, 2023 at 4:34 PM Paolo Bonzini <pbonzini at redhat.com> wrote:
>
> From: Vishal Annapurve <vannapurve at google.com>
>
> Add helpers for x86 guests to invoke the KVM_HC_MAP_GPA_RANGE hypercall,
> which KVM will forward to userspace and thus can be used by tests to
> coordinate private<=>shared conversions between host userspace code and
> guest code.
>
> Signed-off-by: Vishal Annapurve <vannapurve at google.com>
> [sean: drop shared/private helpers (let tests specify flags)]
> Signed-off-by: Sean Christopherson <seanjc at google.com>
> Message-Id: <20231027182217.3615211-29-seanjc at google.com>
> Signed-off-by: Paolo Bonzini <pbonzini at redhat.com>
> ---

Reviewed-by: Fuad Tabba <tabba at google.com>
Tested-by: Fuad Tabba <tabba at google.com>

Cheers,
/fuad

>  .../selftests/kvm/include/x86_64/processor.h      | 15 +++++++++++++++
>  1 file changed, 15 insertions(+)
>
> diff --git a/tools/testing/selftests/kvm/include/x86_64/processor.h b/tools/testing/selftests/kvm/include/x86_64/processor.h
> index 25bc61dac5fb..a84863503fcb 100644
> --- a/tools/testing/selftests/kvm/include/x86_64/processor.h
> +++ b/tools/testing/selftests/kvm/include/x86_64/processor.h
> @@ -15,6 +15,7 @@
>  #include <asm/msr-index.h>
>  #include <asm/prctl.h>
>
> +#include <linux/kvm_para.h>
>  #include <linux/stringify.h>
>
>  #include "../kvm_util.h"
> @@ -1194,6 +1195,20 @@ uint64_t kvm_hypercall(uint64_t nr, uint64_t a0, uint64_t a1, uint64_t a2,
>  uint64_t __xen_hypercall(uint64_t nr, uint64_t a0, void *a1);
>  void xen_hypercall(uint64_t nr, uint64_t a0, void *a1);
>
> +static inline uint64_t __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)
> +{
> +       uint64_t ret = __kvm_hypercall_map_gpa_range(gpa, size, flags);
> +
> +       GUEST_ASSERT(!ret);
> +}
> +
>  void __vm_xsave_require_permission(uint64_t xfeature, const char *name);
>
>  #define vm_xsave_require_permission(xfeature)  \
> --
> 2.39.1
>
>