From: "Toralf Förster" <toralf.foerster@gmx.de>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: kvm@vger.kernel.org
Subject: Re: [PATCH 1/2] arch/x86/kvm/x86.c: remove superflous check condition
Date: Sun, 27 Apr 2014 13:40:38 +0200 [thread overview]
Message-ID: <535CECB6.5070802@gmx.de> (raw)
In-Reply-To: <535CDFBE.5050806@redhat.com>
On 04/27/2014 12:45 PM, Paolo Bonzini wrote:
> Il 27/04/2014 12:30, Toralf Förster ha scritto:
>> Signed-off-by: Toralf Förster <toralf.foerster@gmx.de>
>> ---
>> arch/x86/kvm/x86.c | 23 ++++++++++-------------
>> 1 file changed, 10 insertions(+), 13 deletions(-)
>>
>> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
>> index 8b8fc0b..93cf454 100644
>> --- a/arch/x86/kvm/x86.c
>> +++ b/arch/x86/kvm/x86.c
>> @@ -5680,20 +5680,17 @@ int kvm_hv_hypercall(struct kvm_vcpu *vcpu)
>> kvm_x86_ops->get_cs_db_l_bits(vcpu, &cs_db, &cs_l);
>> longmode = is_long_mode(vcpu) && cs_l == 1;
>>
>> - if (!longmode) {
>> - param = ((u64)kvm_register_read(vcpu, VCPU_REGS_RDX) << 32) |
>> - (kvm_register_read(vcpu, VCPU_REGS_RAX) & 0xffffffff);
>> - ingpa = ((u64)kvm_register_read(vcpu, VCPU_REGS_RBX) << 32) |
>> - (kvm_register_read(vcpu, VCPU_REGS_RCX) & 0xffffffff);
>> - outgpa = ((u64)kvm_register_read(vcpu, VCPU_REGS_RDI) << 32) |
>> - (kvm_register_read(vcpu, VCPU_REGS_RSI) & 0xffffffff);
>> - }
>> #ifdef CONFIG_X86_64
>> - else {
>> - param = kvm_register_read(vcpu, VCPU_REGS_RCX);
>> - ingpa = kvm_register_read(vcpu, VCPU_REGS_RDX);
>> - outgpa = kvm_register_read(vcpu, VCPU_REGS_R8);
>> - }
>> + param = kvm_register_read(vcpu, VCPU_REGS_RCX);
>> + ingpa = kvm_register_read(vcpu, VCPU_REGS_RDX);
>> + outgpa = kvm_register_read(vcpu, VCPU_REGS_R8);
>> +#else
>> + param = ((u64)kvm_register_read(vcpu, VCPU_REGS_RDX) << 32) |
>> + (kvm_register_read(vcpu, VCPU_REGS_RAX) & 0xffffffff);
>> + ingpa = ((u64)kvm_register_read(vcpu, VCPU_REGS_RBX) << 32) |
>> + (kvm_register_read(vcpu, VCPU_REGS_RCX) & 0xffffffff);
>> + outgpa = ((u64)kvm_register_read(vcpu, VCPU_REGS_RDI) << 32) |
>> + (kvm_register_read(vcpu, VCPU_REGS_RSI) & 0xffffffff);
>> #endif
>>
>> code = param & 0xffff;
>>
>
> No, wait, it's only superfluous in the sense that you don't need
> longmode for !CONFIG_X86_64. It's definitely needed for CONFIG_X86_64,
> because the guest can run in 32-bit mode.
>
> Paolo
>
Ah, so the following would work, but looks too ugly, right ? :
#ifdef CONFIG_X86_64
if (!longmode) {
#endif
param = ((u64)kvm_register_read(vcpu, VCPU_REGS_RDX) << 32) |
(kvm_register_read(vcpu, VCPU_REGS_RAX) & 0xffffffff);
ingpa = ((u64)kvm_register_read(vcpu, VCPU_REGS_RBX) << 32) |
(kvm_register_read(vcpu, VCPU_REGS_RCX) & 0xffffffff);
outgpa = ((u64)kvm_register_read(vcpu, VCPU_REGS_RDI) << 32) |
(kvm_register_read(vcpu, VCPU_REGS_RSI) & 0xffffffff);
#ifdef CONFIG_X86_64
}
else {
param = kvm_register_read(vcpu, VCPU_REGS_RCX);
ingpa = kvm_register_read(vcpu, VCPU_REGS_RDX);
outgpa = kvm_register_read(vcpu, VCPU_REGS_R8);
}
#endif
--
Toralf
next prev parent reply other threads:[~2014-04-27 11:40 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-04-27 10:30 [PATCH 1/2] arch/x86/kvm/x86.c: remove superflous check condition Toralf Förster
2014-04-27 10:30 ` [PATCH 2/2] arch/x86/kvm/x86.c: variable longmode ist just used in one place, remove it therefore Toralf Förster
2014-04-27 10:45 ` [PATCH 1/2] arch/x86/kvm/x86.c: remove superflous check condition Paolo Bonzini
2014-04-27 11:40 ` Toralf Förster [this message]
2014-04-27 14:41 ` Paolo Bonzini
2014-04-27 15:29 ` Toralf Förster
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