Subject: Re: [PART1 RFC v2 03/10] svm: Introduce new AVIC VMCB registers
To: Paolo Bonzini <pbonzini@redhat.com>, <rkrcmar@redhat.com>,
        <joro@8bytes.org>, <bp@alien8.de>, <gleb@kernel.org>,
        <alex.williamson@redhat.com>
References: <1457124368-2025-1-git-send-email-Suravee.Suthikulpanit@amd.com>
 <1457124368-2025-4-git-send-email-Suravee.Suthikulpanit@amd.com>
 <56DDA1CF.4080207@redhat.com>
CC: <kvm@vger.kernel.org>, <linux-kernel@vger.kernel.org>, <wei@redhat.com>,
        <sherry.hurwitz@amd.com>
From: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
Message-ID: <56E66B43.1000802@amd.com>
Date: Mon, 14 Mar 2016 14:41:55 +0700
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Hi,

On 03/07/2016 10:44 PM, Paolo Bonzini wrote:
>
> On 04/03/2016 21:46, Suravee Suthikulpanit wrote:
>> >From: Suravee Suthikulpanit<suravee.suthikulpanit@amd.com>
>> >
>> >Introduce new AVIC VMCB registers. Also breakdown int_ctl register
>> >into bit-field for ease of use.
>> >
>> >Signed-off-by: Suravee Suthikulpanit<suravee.suthikulpanit@amd.com>
>> >---
>> >  arch/x86/include/asm/svm.h | 29 ++++++++++++++++++++++++-----
>> >  1 file changed, 24 insertions(+), 5 deletions(-)
>> >
>> >diff --git a/arch/x86/include/asm/svm.h b/arch/x86/include/asm/svm.h
>> >index 6136d99..db5d7af 100644
>> >--- a/arch/x86/include/asm/svm.h
>> >+++ b/arch/x86/include/asm/svm.h
>> >@@ -67,10 +67,24 @@ struct __attribute__ ((__packed__)) vmcb_control_area {
>> >  	u32 asid;
>> >  	u8 tlb_ctl;
>> >  	u8 reserved_2[3];
>> >-	u32 int_ctl;
>> >+	union { /* Offset 0x60 */
>> >+		u32 int_ctl;
>> >+
>> >+		struct __attribute__ ((__packed__)) {
>> >+			u32 v_tpr		: 8,
>> >+			    v_irq		: 1,
>> >+			    reserved_3		: 7,
>> >+			    v_intr_prio		: 4,
>> >+			    v_ign_tpr		: 1,
>> >+			    reserved_4		: 3,
>> >+			    v_intr_masking	: 1,
>> >+			    reserved_5		: 6,
>> >+			    avic_enable		: 1;
> Please do not introduce bitfields and drop patch 4.
>
> Thanks,
>
> Paolo
>

Any particular reason why you do not recommend the use of bit field?

Thanks,
Suravee