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Message-ID: <2c5ac9fd-79f5-bbb4-5798-67a1f9c161b2@linaro.org>
Date:   Mon, 5 Jun 2023 14:48:17 -0500
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From:   Alex Elder <elder@linaro.org>
Subject: Re: [PATCH v13 10/24] gunyah: vm_mgr: Add/remove user memory regions
To:     Elliot Berman <quic_eberman@quicinc.com>,
        Srinivas Kandagatla <srinivas.kandagatla@linaro.org>,
        Prakruthi Deepak Heragu <quic_pheragu@quicinc.com>
Cc:     Murali Nalajala <quic_mnalajal@quicinc.com>,
        Trilok Soni <quic_tsoni@quicinc.com>,
        Srivatsa Vaddagiri <quic_svaddagi@quicinc.com>,
        Carl van Schaik <quic_cvanscha@quicinc.com>,
        Dmitry Baryshkov <dmitry.baryshkov@linaro.org>,
        Bjorn Andersson <andersson@kernel.org>,
        Konrad Dybcio <konrad.dybcio@linaro.org>,
        Arnd Bergmann <arnd@arndb.de>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Jonathan Corbet <corbet@lwn.net>,
        Bagas Sanjaya <bagasdotme@gmail.com>,
        Will Deacon <will@kernel.org>, Andy Gross <agross@kernel.org>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Jassi Brar <jassisinghbrar@gmail.com>,
        linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org
References: <20230509204801.2824351-1-quic_eberman@quicinc.com>
 <20230509204801.2824351-11-quic_eberman@quicinc.com>
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On 5/9/23 3:47 PM, Elliot Berman wrote:
> When launching a virtual machine, Gunyah userspace allocates memory for
> the guest and informs Gunyah about these memory regions through
> SET_USER_MEMORY_REGION ioctl.
> 
> Co-developed-by: Prakruthi Deepak Heragu <quic_pheragu@quicinc.com>
> Signed-off-by: Prakruthi Deepak Heragu <quic_pheragu@quicinc.com>
> Signed-off-by: Elliot Berman <quic_eberman@quicinc.com>

Two minor comments below.  In any case:

Reviewed-by: Alex Elder <elder@linaro.org>

> ---
>   drivers/virt/gunyah/Makefile    |   2 +-
>   drivers/virt/gunyah/vm_mgr.c    |  59 +++++++-
>   drivers/virt/gunyah/vm_mgr.h    |  26 ++++
>   drivers/virt/gunyah/vm_mgr_mm.c | 236 ++++++++++++++++++++++++++++++++
>   include/uapi/linux/gunyah.h     |  37 +++++
>   5 files changed, 356 insertions(+), 4 deletions(-)
>   create mode 100644 drivers/virt/gunyah/vm_mgr_mm.c
> 
> diff --git a/drivers/virt/gunyah/Makefile b/drivers/virt/gunyah/Makefile
> index e47e25895299..bacf78b8fa33 100644
> --- a/drivers/virt/gunyah/Makefile
> +++ b/drivers/virt/gunyah/Makefile
> @@ -1,4 +1,4 @@
>   # SPDX-License-Identifier: GPL-2.0
>   
> -gunyah-y += rsc_mgr.o rsc_mgr_rpc.o vm_mgr.o
> +gunyah-y += rsc_mgr.o rsc_mgr_rpc.o vm_mgr.o vm_mgr_mm.o
>   obj-$(CONFIG_GUNYAH) += gunyah.o
> diff --git a/drivers/virt/gunyah/vm_mgr.c b/drivers/virt/gunyah/vm_mgr.c
> index a43401cb34f7..297427952b8c 100644
> --- a/drivers/virt/gunyah/vm_mgr.c
> +++ b/drivers/virt/gunyah/vm_mgr.c
> @@ -15,6 +15,8 @@
>   
>   #include "vm_mgr.h"
>   
> +static void gh_vm_free(struct work_struct *work);
> +

You could just define gh_vm_free() here rather than declaring
and defining it later.

>   static __must_check struct gh_vm *gh_vm_alloc(struct gh_rm *rm)
>   {
>   	struct gh_vm *ghvm;

. . .

> diff --git a/drivers/virt/gunyah/vm_mgr_mm.c b/drivers/virt/gunyah/vm_mgr_mm.c
> new file mode 100644
> index 000000000000..91109bbf36b3
> --- /dev/null
> +++ b/drivers/virt/gunyah/vm_mgr_mm.c
> @@ -0,0 +1,236 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) 2022-2023 Qualcomm Innovation Center, Inc. All rights reserved.
> + */
> +
> +#define pr_fmt(fmt) "gh_vm_mgr: " fmt
> +
> +#include <linux/gunyah_rsc_mgr.h>
> +#include <linux/mm.h>
> +
> +#include <uapi/linux/gunyah.h>
> +
> +#include "vm_mgr.h"
> +
> +static bool pages_are_mergeable(struct page *a, struct page *b)
> +{
> +	if (page_to_pfn(a) + 1 != page_to_pfn(b))
> +		return false;
> +	if (!zone_device_pages_have_same_pgmap(a, b))
> +		return false;
> +	return true;

Maybe just:

	return zone_device_pages_have_same_pgmap(a, b);

> +}
> +
> +static bool gh_vm_mem_overlap(struct gh_vm_mem *a, u64 addr, u64 size)
> +{
> +	u64 a_end = a->guest_phys_addr + (a->npages << PAGE_SHIFT);
> +	u64 end = addr + size;
> +
> +	return a->guest_phys_addr < end && addr < a_end;
> +}
> +

. . .