linux-kernel - Re: [PATCH 3/4] KVM: x86: hyper-v: Fix the maximum number of sparse banks for XMM fast TLB flush hypercalls

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Message-ID: <YhyoOcz2uAvE9jDN@147dda3edfb6.ant.amazon.com>
Date:   Mon, 28 Feb 2022 11:47:21 +0100
From:   Siddharth Chandrasekaran <sidcha@...zon.de>
To:     Vitaly Kuznetsov <vkuznets@...hat.com>
CC:     <kvm@...r.kernel.org>, Paolo Bonzini <pbonzini@...hat.com>,
        Sean Christopherson <seanjc@...gle.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>,
        <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 3/4] KVM: x86: hyper-v: Fix the maximum number of sparse banks
 for XMM fast TLB flush hypercalls

On Tue, Feb 22, 2022 at 04:46:41PM +0100, Vitaly Kuznetsov wrote:
> CAUTION: This email originated from outside of the organization. Do not click links or open attachments unless you can confirm the sender and know the content is safe.
> 
> 
> 
> When TLB flush hypercalls (HVCALL_FLUSH_VIRTUAL_ADDRESS_{LIST,SPACE}_EX are
> issued in 'XMM fast' mode, the maximum number of allowed sparse_banks is
> not 'HV_HYPERCALL_MAX_XMM_REGISTERS - 1' (5) but twice as many (10) as each
> XMM register is 128 bit long and can hold two 64 bit long banks.
> 
> Fixes: 5974565bc26d ("KVM: x86: kvm_hv_flush_tlb use inputs from XMM registers")
> Signed-off-by: Vitaly Kuznetsov <vkuznets@...hat.com>

Indeed :)

Reviewed-by: Siddharth Chandrasekaran <sidcha@...zon.de>



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