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Subject: Re: [PATCH v8 07/11] x86/tdx: Add HLT support for TDX guest
To:     Josh Poimboeuf <jpoimboe@redhat.com>
Cc:     Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        x86@kernel.org, Paolo Bonzini <pbonzini@redhat.com>,
        David Hildenbrand <david@redhat.com>,
        Andrea Arcangeli <aarcange@redhat.com>,
        Juergen Gross <jgross@suse.com>, Deep Shah <sdeep@vmware.com>,
        VMware Inc <pv-drivers@vmware.com>,
        Vitaly Kuznetsov <vkuznets@redhat.com>,
        Wanpeng Li <wanpengli@tencent.com>,
        Jim Mattson <jmattson@google.com>,
        Joerg Roedel <joro@8bytes.org>, Peter H Anvin <hpa@zytor.com>,
        Dave Hansen <dave.hansen@intel.com>,
        Tony Luck <tony.luck@intel.com>,
        Dan Williams <dan.j.williams@intel.com>,
        Andi Kleen <ak@linux.intel.com>,
        Kirill Shutemov <kirill.shutemov@linux.intel.com>,
        Sean Christopherson <seanjc@google.com>,
        Kuppuswamy Sathyanarayanan <knsathya@kernel.org>,
        linux-kernel@vger.kernel.org
References: <20211005025205.1784480-1-sathyanarayanan.kuppuswamy@linux.intel.com>
 <20211005025205.1784480-8-sathyanarayanan.kuppuswamy@linux.intel.com>
 <20211006191716.pyhwbgfyqugoupmg@treble>
From:   "Kuppuswamy, Sathyanarayanan" 
        <sathyanarayanan.kuppuswamy@linux.intel.com>
Message-ID: <bec1c79c-3c45-91ad-a46e-6c79918f4eca@linux.intel.com>
Date:   Thu, 7 Oct 2021 12:25:57 -0700
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On 10/6/21 12:17 PM, Josh Poimboeuf wrote:
> I'm having trouble following this last comment, does it mean there's no
> way to return the error back to the #VE handler when this is called in
> #VE context?  Seems like that would be any easy problem to solve by
> shuffling the functions a bit.

Currently tdx_*halt() calls are used in both pv_ops and
tdx_handle_virtualization_exception(). If it is just
tdx_handle_virtualization_exception() then we can just return the error
and let exc_virtualization_exception() handle error using ve_raise_fault().

But in this case, since pv_ops is also involved, instead of defining
two different halt handler functions for pv_ops and
exc_virtualization_exception( we just use WARN_ON to report
the error.


-- 
Sathyanarayanan Kuppuswamy
Linux Kernel Developer