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From: Siddharth Chandrasekaran <sidcha@amazon.de>
To: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: <kvm@vger.kernel.org>, Paolo Bonzini <pbonzini@redhat.com>,
	Sean Christopherson <seanjc@google.com>,
	Wanpeng Li <wanpengli@tencent.com>,
	Jim Mattson <jmattson@google.com>, <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 4/4] KVM: x86: hyper-v: HVCALL_SEND_IPI_EX is an XMM fast hypercall
Date: Mon, 28 Feb 2022 11:48:26 +0100	[thread overview]
Message-ID: <YhyoevsjEhNfcwWY@147dda3edfb6.ant.amazon.com> (raw)
In-Reply-To: <20220222154642.684285-5-vkuznets@redhat.com>

On Tue, Feb 22, 2022 at 04:46:42PM +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.
> 
> 
> 
> It has been proven on practice that at least Windows Server 2019 tries
> using HVCALL_SEND_IPI_EX in 'XMM fast' mode when it has more than 64 vCPUs
> and it needs to send an IPI to a vCPU > 63. Similarly to other XMM Fast
> hypercalls (HVCALL_FLUSH_VIRTUAL_ADDRESS_{LIST,SPACE}{,_EX}), this
> information is missing in TLFS as of 6.0b. Currently, KVM returns an error
> (HV_STATUS_INVALID_HYPERCALL_INPUT) and Windows crashes.
> 
> Note, HVCALL_SEND_IPI is a 'standard' fast hypercall (not 'XMM fast') as
> all its parameters fit into RDX:R8 and this is handled by KVM correctly.
> 
> Fixes: d8f5537a8816 ("KVM: hyper-v: Advertise support for fast XMM hypercalls")
> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>

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



Amazon Development Center Germany GmbH
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  parent reply	other threads:[~2022-02-28 10:48 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-02-22 15:46 [PATCH 0/4] KVM: x86: hyper-v: XMM fast hypercalls fixes Vitaly Kuznetsov
2022-02-22 15:46 ` [PATCH 1/4] KVM: x86: hyper-v: Drop redundant 'ex' parameter from kvm_hv_send_ipi() Vitaly Kuznetsov
2022-02-25 18:21   ` Maxim Levitsky
2022-02-28  9:58     ` Vitaly Kuznetsov
2022-02-28 10:45   ` Siddharth Chandrasekaran
2022-02-22 15:46 ` [PATCH 2/4] KVM: x86: hyper-v: Drop redundant 'ex' parameter from kvm_hv_flush_tlb() Vitaly Kuznetsov
2022-02-25 18:22   ` Maxim Levitsky
2022-02-28 10:46   ` Siddharth Chandrasekaran
2022-02-22 15:46 ` [PATCH 3/4] KVM: x86: hyper-v: Fix the maximum number of sparse banks for XMM fast TLB flush hypercalls Vitaly Kuznetsov
2022-02-28 10:47   ` Siddharth Chandrasekaran
2022-02-22 15:46 ` [PATCH 4/4] KVM: x86: hyper-v: HVCALL_SEND_IPI_EX is an XMM fast hypercall Vitaly Kuznetsov
2022-02-25 18:33   ` Maxim Levitsky
2022-02-28 10:02     ` Vitaly Kuznetsov
2022-02-28 10:48   ` Siddharth Chandrasekaran [this message]
2022-02-25 11:55 ` [PATCH 0/4] KVM: x86: hyper-v: XMM fast hypercalls fixes Paolo Bonzini
2022-02-25 13:13   ` Vitaly Kuznetsov
2022-02-25 13:17     ` Paolo Bonzini
2022-02-28 10:52       ` Siddharth Chandrasekaran
2022-02-28 11:09         ` Vitaly Kuznetsov
2022-02-28 16:18           ` Siddharth Chandrasekaran

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