Subject: Re: [PATCH v5 6/9] irqchip/gic-v3: Parse and export virtual GIC
 information
To: Julien Grall <julien.grall@arm.com>, Hanjun Guo <hanjun.guo@linaro.org>,
        kvmarm@lists.cs.columbia.edu
References: <1459769860-6629-1-git-send-email-julien.grall@arm.com>
 <1459769860-6629-7-git-send-email-julien.grall@arm.com>
 <570B35DA.5050600@linaro.org> <570BB461.4040704@arm.com>
Cc: al.stone@linaro.org, kvm@vger.kernel.org, marc.zyngier@arm.com,
        linux-kernel@vger.kernel.org, fu.wei@linaro.org,
        Thomas Gleixner <tglx@linutronix.de>,
        Jason Cooper <jason@lakedaemon.net>,
        linux-arm-kernel@lists.infradead.org, gg@slimlogic.co.uk
From: Shanker Donthineni <shankerd@codeaurora.org>
Message-ID: <570BC1ED.9080200@codeaurora.org>
Date: Mon, 11 Apr 2016 10:25:33 -0500
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Hi Julien,

On 04/11/2016 09:27 AM, Julien Grall wrote:
> Hello Hanjun,
>
> On 11/04/16 06:27, Hanjun Guo wrote:
>> On 2016/4/4 19:37, Julien Grall wrote:
>>> +static void __init gic_acpi_setup_kvm_info(void)
>>> +{
>>> +    int irq;
>>> +
>>> +    if (!gic_acpi_collect_virt_info()) {
>>> +        pr_warn("Unable to get hardware information used for
>>> virtualization\n");
>>> +        return;
>>> +    }
>>> +
>>> +    gic_v3_kvm_info.type = GIC_V3;
>>> +
>>> +    irq = acpi_register_gsi(NULL, acpi_data.maint_irq,
>>> +                acpi_data.maint_irq_mode,
>>> +                ACPI_ACTIVE_HIGH);
>>> +    if (irq <= 0)
>>> +        return;
>>> +
>>> +    gic_v3_kvm_info.maint_irq = irq;
>>> +
>>> +    if (acpi_data.vcpu_base) {
>>
>> Sorry, I'm not familiar with KVM, but I got a question here, will
>> KVM works without valid vcpu_base in GICv3 mode?
>
Yes, KVM works without vcpu_base in GICv3 mode. The vcpu_base will be used
for emulatingvGICv2 feature. The vGICv3 emulation isdone through the
system registers.

> vcpu_base is only required for supporting GICv2 on GICv3.
>
Yes, you are right,

> Regards,
>

-- 
Shanker Donthineni
Qualcomm Technologies, Inc. on behalf of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project