Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Date:   Mon, 2 Aug 2021 14:07:59 +0200
From:   Joerg Roedel <joro@8bytes.org>
To:     Tianyu Lan <ltykernel@gmail.com>
Cc:     kys@microsoft.com, haiyangz@microsoft.com, sthemmin@microsoft.com,
        wei.liu@kernel.org, decui@microsoft.com, tglx@linutronix.de,
        mingo@redhat.com, bp@alien8.de, x86@kernel.org, hpa@zytor.com,
        dave.hansen@linux.intel.com, luto@kernel.org, peterz@infradead.org,
        konrad.wilk@oracle.com, boris.ostrovsky@oracle.com,
        jgross@suse.com, sstabellini@kernel.org, will@kernel.org,
        davem@davemloft.net, kuba@kernel.org, jejb@linux.ibm.com,
        martin.petersen@oracle.com, arnd@arndb.de, hch@lst.de,
        m.szyprowski@samsung.com, robin.murphy@arm.com,
        thomas.lendacky@amd.com, brijesh.singh@amd.com, ardb@kernel.org,
        Tianyu.Lan@microsoft.com, rientjes@google.com,
        martin.b.radev@gmail.com, akpm@linux-foundation.org,
        rppt@kernel.org, kirill.shutemov@linux.intel.com,
        aneesh.kumar@linux.ibm.com, krish.sadhukhan@oracle.com,
        saravanand@fb.com, xen-devel@lists.xenproject.org,
        pgonda@google.com, david@redhat.com, keescook@chromium.org,
        hannes@cmpxchg.org, sfr@canb.auug.org.au,
        michael.h.kelley@microsoft.com, iommu@lists.linux-foundation.org,
        linux-arch@vger.kernel.org, linux-hyperv@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org,
        netdev@vger.kernel.org, vkuznets@redhat.com, anparri@microsoft.com
Subject: Re: [PATCH 04/13] HV: Mark vmbus ring buffer visible to host in
 Isolation VM
Message-ID: <YQfgH04t2SqacnHn@8bytes.org>
References: <20210728145232.285861-1-ltykernel@gmail.com>
 <20210728145232.285861-5-ltykernel@gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20210728145232.285861-5-ltykernel@gmail.com>
Precedence: bulk

On Wed, Jul 28, 2021 at 10:52:19AM -0400, Tianyu Lan wrote:
> +	if (type == HV_GPADL_BUFFER)
> +		index = 0;
> +	else
> +		index = channel->gpadl_range[1].gpadlhandle ? 2 : 1;

Hmm... This doesn't look very robust. Can you set fixed indexes for
different buffer types? HV_GPADL_BUFFER already has fixed index 0. But
as it is implemented here you risk that index 2 gets overwritten by
subsequent calls.