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Date:   Fri, 21 Apr 2023 21:25:47 +0000
From:   Wei Liu <wei.liu@kernel.org>
To:     Lorenzo Pieralisi <lpieralisi@kernel.org>
Cc:     Dexuan Cui <decui@microsoft.com>, kys@microsoft.com,
        haiyangz@microsoft.com, wei.liu@kernel.org, kw@linux.com,
        robh@kernel.org, bhelgaas@google.com, linux-hyperv@vger.kernel.org,
        linux-pci@vger.kernel.org, mikelley@microsoft.com,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] PCI: hv: Replace retarget_msi_interrupt_params with
 hyperv_pcpu_input_arg
Message-ID: <ZEL/W59LHx+5o4r4@liuwe-devbox-debian-v2>
References: <20230421013025.17152-1-decui@microsoft.com>
 <ZEJdSXv6IwSxPp9r@lpieralisi>
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On Fri, Apr 21, 2023 at 11:54:17AM +0200, Lorenzo Pieralisi wrote:
> On Thu, Apr 20, 2023 at 06:30:25PM -0700, Dexuan Cui wrote:
> > 4 commits are involved here:
> > A (2016): commit 0de8ce3ee8e3 ("PCI: hv: Allocate physically contiguous hypercall params buffer")
> > B (2017): commit be66b6736591 ("PCI: hv: Use page allocation for hbus structure")
> > C (2019): commit 877b911a5ba0 ("PCI: hv: Avoid a kmemleak false positive caused by the hbus buffer")
> > D (2018): commit 68bb7bfb7985 ("X86/Hyper-V: Enable IPI enlightenments")
> > 
> > Patch D introduced the per-CPU hypercall input page "hyperv_pcpu_input_arg"
> > in 2018. With patch D, we no longer need the per-Hyper-V-PCI-bus hypercall
> > input page "hbus->retarget_msi_interrupt_params" that was added in patch A,
> > and the issue addressed by patch B is no longer an issue, and we can also
> > get rid of patch C.
> > 
> > The change here is required for PCI device assignment to work for
> > Confidential VMs (CVMs) running without a paravisor, because otherwise we
> > would have to call set_memory_decrypted() for
> > "hbus->retarget_msi_interrupt_params" before calling the hypercall
> > HVCALL_RETARGET_INTERRUPT.
> > 
> > Signed-off-by: Dexuan Cui <decui@microsoft.com>
> > Reviewed-by: Michael Kelley <mikelley@microsoft.com>
> > ---
> > 
> > Changes in v2:
> >   Fixed the inaccuracy in the commit message (Thanks Michael):
> >     "Confidential VMs (CVMs)" -> "Confidential VMs (CVMs) running without a paravisor".
> > 
> >   Added Michael's Reviewed-by.
> > 
> >  drivers/pci/controller/pci-hyperv.c | 48 +++++------------------------
> >  1 file changed, 7 insertions(+), 41 deletions(-)
> 
> Acked-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
> 

Applied to hyperv-next. Thanks.