Re: [PATCH v8 05/10] KVM: selftests: Add support for protected vm_vaddr_* allocations

[Itaru Kitayama]

On Fri, Feb 02, 2024 at 04:09:11PM -0800, Sean Christopherson wrote:
> From: Michael Roth <michael.roth@xxxxxxx>
> 
> Test programs may wish to allocate shared vaddrs for things like
> sharing memory with the guest. Since protected vms will have their
> memory encrypted by default an interface is needed to explicitly
> request shared pages.
> 
> Implement this by splitting the common code out from vm_vaddr_alloc()
> and introducing a new vm_vaddr_alloc_shared().
> 
> Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
> Cc: Sean Christopherson <seanjc@xxxxxxxxxx>
> Cc: Vishal Annapurve <vannapurve@xxxxxxxxxx>
> Cc: Ackerly Tng <ackerleytng@xxxxxxxxxx>
> cc: Andrew Jones <andrew.jones@xxxxxxxxx>
> Cc: Tom Lendacky <thomas.lendacky@xxxxxxx>
> Cc: Michael Roth <michael.roth@xxxxxxx>
> Signed-off-by: Michael Roth <michael.roth@xxxxxxx>
> Signed-off-by: Peter Gonda <pgonda@xxxxxxxxxx>
> Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
> ---
>  .../selftests/kvm/include/kvm_util_base.h     |  3 +++
>  tools/testing/selftests/kvm/lib/kvm_util.c    | 26 +++++++++++++++----
>  2 files changed, 24 insertions(+), 5 deletions(-)
> 
> diff --git a/tools/testing/selftests/kvm/include/kvm_util_base.h b/tools/testing/selftests/kvm/include/kvm_util_base.h
> index a82149305349..cb3159af6db3 100644
> --- a/tools/testing/selftests/kvm/include/kvm_util_base.h
> +++ b/tools/testing/selftests/kvm/include/kvm_util_base.h
> @@ -590,6 +590,9 @@ vm_vaddr_t vm_vaddr_unused_gap(struct kvm_vm *vm, size_t sz, vm_vaddr_t vaddr_mi
>  vm_vaddr_t vm_vaddr_alloc(struct kvm_vm *vm, size_t sz, vm_vaddr_t vaddr_min);
>  vm_vaddr_t __vm_vaddr_alloc(struct kvm_vm *vm, size_t sz, vm_vaddr_t vaddr_min,
>  			    enum kvm_mem_region_type type);
> +vm_vaddr_t vm_vaddr_alloc_shared(struct kvm_vm *vm, size_t sz,
> +				 vm_vaddr_t vaddr_min,
> +				 enum kvm_mem_region_type type);
>  vm_vaddr_t vm_vaddr_alloc_pages(struct kvm_vm *vm, int nr_pages);
>  vm_vaddr_t __vm_vaddr_alloc_page(struct kvm_vm *vm,
>  				 enum kvm_mem_region_type type);
> diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
> index ea677aa019ef..e7f4f84f2e68 100644
> --- a/tools/testing/selftests/kvm/lib/kvm_util.c
> +++ b/tools/testing/selftests/kvm/lib/kvm_util.c
> @@ -1431,15 +1431,17 @@ vm_vaddr_t vm_vaddr_unused_gap(struct kvm_vm *vm, size_t sz,
>  	return pgidx_start * vm->page_size;
>  }
>  
> -vm_vaddr_t __vm_vaddr_alloc(struct kvm_vm *vm, size_t sz, vm_vaddr_t vaddr_min,
> -			    enum kvm_mem_region_type type)
> +static vm_vaddr_t ____vm_vaddr_alloc(struct kvm_vm *vm, size_t sz,
> +				     vm_vaddr_t vaddr_min,
> +				     enum kvm_mem_region_type type,
> +				     bool protected)
>  {
>  	uint64_t pages = (sz >> vm->page_shift) + ((sz % vm->page_size) != 0);
>  
>  	virt_pgd_alloc(vm);
> -	vm_paddr_t paddr = vm_phy_pages_alloc(vm, pages,
> -					      KVM_UTIL_MIN_PFN * vm->page_size,
> -					      vm->memslots[type]);
> +	vm_paddr_t paddr = __vm_phy_pages_alloc(vm, pages,
> +						KVM_UTIL_MIN_PFN * vm->page_size,
> +						vm->memslots[type], protected);
>  
>  	/*
>  	 * Find an unused range of virtual page addresses of at least
> @@ -1459,6 +1461,20 @@ vm_vaddr_t __vm_vaddr_alloc(struct kvm_vm *vm, size_t sz, vm_vaddr_t vaddr_min,
>  	return vaddr_start;
>  }
>  
> +vm_vaddr_t __vm_vaddr_alloc(struct kvm_vm *vm, size_t sz, vm_vaddr_t vaddr_min,
> +			    enum kvm_mem_region_type type)
> +{
> +	return ____vm_vaddr_alloc(vm, sz, vaddr_min, type,
> +				  vm_arch_has_protected_memory(vm));
> +}
> +
> +vm_vaddr_t vm_vaddr_alloc_shared(struct kvm_vm *vm, size_t sz,
> +				 vm_vaddr_t vaddr_min,
> +				 enum kvm_mem_region_type type)
> +{
> +	return ____vm_vaddr_alloc(vm, sz, vaddr_min, type, false);
> +}
> +
>  /*
>   * VM Virtual Address Allocate
>   *
Reviewied-by: Itaru Kitayama <itaru.kitayama@xxxxxxxxxxx>

> -- 
> 2.43.0.594.gd9cf4e227d-goog
>