Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:18 as permitted sender) client-ip=2620:137:e000::1:18;
Message-ID: <2ed5c9cc316950a5a47ee714715b7980f358a140.camel@intel.com>
Subject: Re: [PATCH v5 3/3] x86/tdx: Add Quote generation support
From:   Kai Huang <kai.huang@intel.com>
To:     Sathyanarayanan Kuppuswamy 
        <sathyanarayanan.kuppuswamy@linux.intel.com>,
        Dave Hansen <dave.hansen@intel.com>,
        "Kirill A. Shutemov" <kirill@shutemov.name>
Cc:     Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        Dave Hansen <dave.hansen@linux.intel.com>, x86@kernel.org,
        "H . Peter Anvin" <hpa@zytor.com>,
        "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>,
        Tony Luck <tony.luck@intel.com>,
        Andi Kleen <ak@linux.intel.com>,
        Wander Lairson Costa <wander@redhat.com>,
        Isaku Yamahata <isaku.yamahata@gmail.com>,
        marcelo.cerri@canonical.com, tim.gardner@canonical.com,
        khalid.elmously@canonical.com, philip.cox@canonical.com,
        linux-kernel@vger.kernel.org
Date:   Thu, 05 May 2022 11:28:32 +1200
In-Reply-To: <40ccd0f0-35a1-5aa7-9e51-25ab196d79e5@linux.intel.com>
References: <20220501183500.2242828-1-sathyanarayanan.kuppuswamy@linux.intel.com>
         <20220501183500.2242828-4-sathyanarayanan.kuppuswamy@linux.intel.com>
         <243e918c523320ba3d216cbe22d24fe5ce33f370.camel@intel.com>
         <20220503012721.ok7fbvxmnvsr6qny@box.shutemov.name>
         <58d07b2d-cef5-17ed-9c57-e12fe5665e04@intel.com>
         <40ccd0f0-35a1-5aa7-9e51-25ab196d79e5@linux.intel.com>
Content-Type: text/plain; charset="UTF-8"
User-Agent: Evolution 3.42.4 (3.42.4-1.fc35) 
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

On Wed, 2022-05-04 at 15:49 -0700, Sathyanarayanan Kuppuswamy wrote:
> --- a/arch/x86/coco/tdx/tdx.c
> +++ b/arch/x86/coco/tdx/tdx.c
> @@ -15,6 +15,7 @@
>   #include <asm/idtentry.h>
>   #include <asm/irq_regs.h>
>   #include <asm/desc.h>
> +#include <asm/io.h>
> 
>   /* TDX module Call Leaf IDs */
>   #define TDX_GET_INFO                   1
> @@ -680,8 +681,15 @@ static bool try_accept_one(phys_addr_t *start, 
> unsigned long len,
>    */
>   static bool tdx_enc_status_changed(unsigned long vaddr, int numpages, 
> bool enc)
>   {
> -       phys_addr_t start = __pa(vaddr);
> -       phys_addr_t end   = __pa(vaddr + numpages * PAGE_SIZE);
> +       phys_addr_t start;
> +       phys_addr_t end;
> +
> +       if (is_vmalloc_addr((void *)vaddr))
> +               start =  page_to_phys(vmalloc_to_page((void*)vaddr));
> +       else
> +               start = __pa(vaddr);
> +
> +       end = start + numpages * PAGE_SIZE;
> 
>          if (!enc) {
>                  /* Set the shared (decrypted) bits: */

Looks set_memory_decrypted() only works for direct-mapping, so you should not
use this.  Instead, you can pass shared bit in 'prot' argument (using
pgprot_decrypted()) when you call vmap(), and explicitly call MapGPA().

-- 
Thanks,
-Kai