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Message-ID: <cbc30b0ece76cc02cbfa20321ad9285f2322dfe6.camel@intel.com>
Subject: Re: [PATCH v5 08/22] x86/virt/tdx: Shut down TDX module in case of
 error
From:   Kai Huang <kai.huang@intel.com>
To:     Dave Hansen <dave.hansen@intel.com>, linux-kernel@vger.kernel.org,
        kvm@vger.kernel.org
Cc:     seanjc@google.com, pbonzini@redhat.com, len.brown@intel.com,
        tony.luck@intel.com, rafael.j.wysocki@intel.com,
        reinette.chatre@intel.com, dan.j.williams@intel.com,
        peterz@infradead.org, ak@linux.intel.com,
        kirill.shutemov@linux.intel.com,
        sathyanarayanan.kuppuswamy@linux.intel.com,
        isaku.yamahata@intel.com
Date:   Tue, 28 Jun 2022 12:11:38 +1200
In-Reply-To: <606f7526-23b8-a114-020f-b5fcdeecf90b@intel.com>
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On Mon, 2022-06-27 at 17:03 -0700, Dave Hansen wrote:
> On 6/27/22 16:59, Kai Huang wrote:
> > If so,  in the assembly, I think we can just XOR TDX_SW_ERROR to the %r=
ax and
> > return %rax:
> >=20
> > 2:
> >         /*
> > 	 * SEAMCALL caused #GP or #UD.  By reaching here %eax contains
> > 	 * the trap number.  Convert trap number to TDX error code by setting
> > 	 * TDX_SW_ERROR to the high 32-bits of %rax.
> > 	 */
> > 	xorq	$TDX_SW_ERROR, %rax
> >=20
> > How does this look?
>=20
> I guess it doesn't matter if you know the things being masked together
> are padded correctly, but I probably would have done a straight OR, not X=
OR.
>=20
> Otherwise, I think that looks OK.  Simplifies the assembly for sure.

Right straight OR is better.  Thanks.

--=20
Thanks,
-Kai