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Subject: Re: [PATCH v1 4/8] x86/tdx: Add arch_has_restricted_memory_access for
 TDX
To:     Andi Kleen <ak@linux.intel.com>, mst@redhat.com
Cc:     jasowang@redhat.com, virtualization@lists.linux-foundation.org,
        hch@lst.de, m.szyprowski@samsung.com, robin.murphy@arm.com,
        iommu@lists.linux-foundation.org, x86@kernel.org,
        jpoimboe@redhat.com, linux-kernel@vger.kernel.org
References: <20210603004133.4079390-1-ak@linux.intel.com>
 <20210603004133.4079390-5-ak@linux.intel.com>
From:   "Kuppuswamy, Sathyanarayanan" 
        <sathyanarayanan.kuppuswamy@linux.intel.com>
Message-ID: <2dd6a4a1-e5f7-23e2-9c5b-abfe8ff20e79@linux.intel.com>
Date:   Wed, 2 Jun 2021 21:02:28 -0700
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On 6/2/21 5:41 PM, Andi Kleen wrote:
> +int arch_has_restricted_virtio_memory_access(void)
> +{
> +	return is_tdx_guest();
> +}
> +EXPORT_SYMBOL_GPL(arch_has_restricted_virtio_memory_access);
> +

This function definition had to be removed from arch/x86/mm/mem_encrypt.c.

Otherwise, if you enable both CONFIG_AMD_MEM_ENCRYPT,
CONFIG_X86_MEM_ENCRYPT_COMMON it will generate multiple definition error.

--- a/arch/x86/mm/mem_encrypt.c
+++ b/arch/x86/mm/mem_encrypt.c
@@ -493,9 +493,3 @@ void __init amd_mem_encrypt_init(void)

         print_mem_encrypt_feature_info();
  }
-
-int arch_has_restricted_virtio_memory_access(void)
-{
-       return sev_active();
-}
-EXPORT_SYMBOL_GPL(arch_has_restricted_virtio_memory_access);

--- a/arch/x86/mm/mem_encrypt_common.c
+++ b/arch/x86/mm/mem_encrypt_common.c
@@ -40,7 +40,7 @@ void __init mem_encrypt_init(void)

  int arch_has_restricted_virtio_memory_access(void)
  {
-       return is_tdx_guest();
+       return (is_tdx_guest() || sev_active());
  }
  EXPORT_SYMBOL_GPL(arch_has_restricted_virtio_memory_access);


-- 
Sathyanarayanan Kuppuswamy
Linux Kernel Developer