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Message-ID: <1536589263.11460.59.camel@intel.com>
Subject: Re: [PATCH 1/13] KVM: Add tlb_remote_flush_with_range callback in
 kvm_x86_ops
From:   Sean Christopherson <sean.j.christopherson@intel.com>
To:     Tianyu Lan <Tianyu.Lan@microsoft.com>
Cc:     KY Srinivasan <kys@microsoft.com>,
        Haiyang Zhang <haiyangz@microsoft.com>,
        Stephen Hemminger <sthemmin@microsoft.com>,
        "tglx@linutronix.de" <tglx@linutronix.de>,
        "mingo@redhat.com" <mingo@redhat.com>,
        "hpa@zytor.com" <hpa@zytor.com>, "x86@kernel.org" <x86@kernel.org>,
        "pbonzini@redhat.com" <pbonzini@redhat.com>,
        "rkrcmar@redhat.com" <rkrcmar@redhat.com>,
        "devel@linuxdriverproject.org" <devel@linuxdriverproject.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "kvm@vger.kernel.org" <kvm@vger.kernel.org>,
        "Michael Kelley (EOSG)" <Michael.H.Kelley@microsoft.com>,
        vkuznets <vkuznets@redhat.com>,
        Jork Loeser <Jork.Loeser@microsoft.com>
Date:   Mon, 10 Sep 2018 07:21:03 -0700
In-Reply-To: <20180910083806.65177-2-Tianyu.Lan@microsoft.com>
References: <20180910083806.65177-1-Tianyu.Lan@microsoft.com>
         <20180910083806.65177-2-Tianyu.Lan@microsoft.com>
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On Mon, 2018-09-10 at 08:38 +0000, Tianyu Lan wrote:
> Add flush range call back in the kvm_x86_ops and platform can use it
> to register its associated function. The parameter "kvm_tlb_range"
> accepts a single range and flush list which contains a list of ranges.
> 
> Signed-off-by: Lan Tianyu <Tianyu.Lan@microsoft.com>
> ---
>  arch/x86/include/asm/kvm_host.h | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> index e12916e7c2fb..dcdf8cc16388 100644
> --- a/arch/x86/include/asm/kvm_host.h
> +++ b/arch/x86/include/asm/kvm_host.h
> @@ -402,6 +402,12 @@ struct kvm_mmu {
>  	u64 pdptrs[4]; /* pae */
>  };
>  
> +struct kvm_tlb_range {
> +	u64 start_gfn;
> +	u64 end_gfn;

IMO this struct and all functions should pass around the number of pages
instead of end_gfn to avoid confusion as to whether end_gfn is inclusive
or exlusive.

> +	struct list_head *flush_list;
> +};
> +
>  enum pmc_type {
>  	KVM_PMC_GP = 0,
>  	KVM_PMC_FIXED,
> @@ -991,6 +997,8 @@ struct kvm_x86_ops {
>  
>  	void (*tlb_flush)(struct kvm_vcpu *vcpu, bool invalidate_gpa);
>  	int  (*tlb_remote_flush)(struct kvm *kvm);
> +	int  (*tlb_remote_flush_with_range)(struct kvm *kvm,
> +			struct kvm_tlb_range *range);
>  
>  	/*
>  	 * Flush any TLB entries associated with the given GVA.