Message-ID: <3fe1023a-99b7-e905-20c1-12a51b57f701@linaro.org>
Date:   Tue, 21 Mar 2023 20:19:48 +0000
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Subject: Re: [PATCH v11 16/26] firmware: qcom_scm: Register Gunyah platform
 ops
Content-Language: en-US
To:     Elliot Berman <quic_eberman@quicinc.com>,
        Alex Elder <elder@linaro.org>, Andy Gross <agross@kernel.org>,
        Bjorn Andersson <andersson@kernel.org>,
        Konrad Dybcio <konrad.dybcio@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>,
        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>,
        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: <20230304010632.2127470-1-quic_eberman@quicinc.com>
 <20230304010632.2127470-17-quic_eberman@quicinc.com>
 <6c2e3fac-1bd8-be10-6e10-e200ee9b55f2@linaro.org>
 <bc68f88e-81fd-e24c-30b6-73bff4652bae@quicinc.com>
From:   Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
In-Reply-To: <bc68f88e-81fd-e24c-30b6-73bff4652bae@quicinc.com>
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On 21/03/2023 18:40, Elliot Berman wrote:
> 
> 
> On 3/21/2023 7:24 AM, Srinivas Kandagatla wrote:
>> Hi Elliot,
>>
>> On 04/03/2023 01:06, Elliot Berman wrote:
>>> Qualcomm platforms have a firmware entity which performs access control
>>> to physical pages. Dynamically started Gunyah virtual machines use the
>>> QCOM_SCM_RM_MANAGED_VMID for access. Linux thus needs to assign access
>>> to the memory used by guest VMs. Gunyah doesn't do this operation for us
>>> since it is the current VM (typically VMID_HLOS) delegating the access
>>> and not Gunyah itself. Use the Gunyah platform ops to achieve this so
>>> that only Qualcomm platforms attempt to make the needed SCM calls.
>>>
>>> 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>
>>> ---
>>>   drivers/firmware/Kconfig       |   2 +
>>>   drivers/firmware/qcom_scm.c    | 100 +++++++++++++++++++++++++++++++++
>>>   include/linux/gunyah_rsc_mgr.h |   2 +-
>>>   3 files changed, 103 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig
>>> index b59e3041fd62..b888068ff6f2 100644
>>> --- a/drivers/firmware/Kconfig
>>> +++ b/drivers/firmware/Kconfig
>>> @@ -214,6 +214,8 @@ config MTK_ADSP_IPC
>>>   config QCOM_SCM
>>>       tristate
>>> +    select VIRT_DRIVERS
>>> +    select GUNYAH_PLATFORM_HOOKS
>>>
>>
>> I still have concerns with this selects in Kconfig on older Qualcomm 
>> platforms that use SCM and do not have GUNYAH.
>>
>> In our last discussing you mentioned the requirement for
>> "CONFIG_GUNYAH=y and CONFIG_QCOM_SCM=m"
>>
>> I think that should be doable and remove selecting if you can make a 
>> separate GUNYAH_QCOM_PLATFORM_HOOKS driver
>>
>> Does this work?
> 
> This works for Android and all the Qualcomm vendor (downstream) 
> platforms where we can explicitly load modules. I don't think this 
> module would be implicitly loaded by any kernel mechanism.

We could also load this module based on UUID match at the gunyah core 
level too, if that helps.


--srini

> 
>>  >----------------------->cut<-------------------------------
>>  From 1fb7995aecf17caefd09ffb516579bc4ac9ac301 Mon Sep 17 00:00:00 2001
>> From: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
>> Date: Tue, 21 Mar 2023 13:34:02 +0000
>> Subject: [PATCH] virt: gunyah: add qcom platform hooks
>>
>> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
>> ---
>>   drivers/firmware/Kconfig                      |  2 --
>>   drivers/firmware/qcom_scm.c                   | 14 +++-----
>>   drivers/virt/gunyah/Kconfig                   |  5 +++
>>   drivers/virt/gunyah/Makefile                  |  1 +
>>   .../virt/gunyah/gunyah_qcom_platform_hooks.c  | 35 +++++++++++++++++++
>>   include/linux/firmware/qcom/qcom_scm.h        |  3 ++
>>   6 files changed, 48 insertions(+), 12 deletions(-)
>>   create mode 100644 drivers/virt/gunyah/gunyah_qcom_platform_hooks.c
>>
>> diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig
>> index b888068ff6f2..b59e3041fd62 100644
>> --- a/drivers/firmware/Kconfig
>> +++ b/drivers/firmware/Kconfig
>> @@ -214,8 +214,6 @@ config MTK_ADSP_IPC
>>
>>   config QCOM_SCM
>>       tristate
>> -    select VIRT_DRIVERS
>> -    select GUNYAH_PLATFORM_HOOKS
>>
>>   config QCOM_SCM_DOWNLOAD_MODE_DEFAULT
>>       bool "Qualcomm download mode enabled by default"
>> diff --git a/drivers/firmware/qcom_scm.c b/drivers/firmware/qcom_scm.c
>> index 5273cf64ee2a..194ea2bc9a1d 100644
>> --- a/drivers/firmware/qcom_scm.c
>> +++ b/drivers/firmware/qcom_scm.c
>> @@ -1301,7 +1301,7 @@ int qcom_scm_lmh_dcvsh(u32 payload_fn, u32 
>> payload_reg, u32 payload_val,
>>   }
>>   EXPORT_SYMBOL(qcom_scm_lmh_dcvsh);
>>
>> -static int qcom_scm_gh_rm_pre_mem_share(struct gh_rm *rm, struct 
>> gh_rm_mem_parcel *mem_parcel)
>> +int qcom_scm_gh_rm_pre_mem_share(struct gh_rm_mem_parcel *mem_parcel)
>>   {
>>       struct qcom_scm_vmperm *new_perms;
>>       u64 src, src_cpy;
>> @@ -1359,8 +1359,9 @@ static int qcom_scm_gh_rm_pre_mem_share(struct 
>> gh_rm *rm, struct gh_rm_mem_parce
>>       kfree(new_perms);
>>       return ret;
>>   }
>> +EXPORT_SYMBOL_GPL(qcom_scm_gh_rm_pre_mem_share);
>>
>> -static int qcom_scm_gh_rm_post_mem_reclaim(struct gh_rm *rm, struct 
>> gh_rm_mem_parcel *mem_parcel)
>> +int qcom_scm_gh_rm_post_mem_reclaim(struct gh_rm_mem_parcel *mem_parcel)
>>   {
>>       struct qcom_scm_vmperm new_perms;
>>       u64 src = 0, src_cpy;
>> @@ -1388,11 +1389,7 @@ static int 
>> qcom_scm_gh_rm_post_mem_reclaim(struct gh_rm *rm, struct gh_rm_mem_pa
>>
>>       return ret;
>>   }
>> -
>> -static struct gh_rm_platform_ops qcom_scm_gh_rm_platform_ops = {
>> -    .pre_mem_share = qcom_scm_gh_rm_pre_mem_share,
>> -    .post_mem_reclaim = qcom_scm_gh_rm_post_mem_reclaim,
>> -};
>> +EXPORT_SYMBOL_GPL(qcom_scm_gh_rm_post_mem_reclaim);
>>
>>   static int qcom_scm_find_dload_address(struct device *dev, u64 *addr)
>>   {
>> @@ -1597,9 +1594,6 @@ static int qcom_scm_probe(struct platform_device 
>> *pdev)
>>       if (download_mode)
>>           qcom_scm_set_download_mode(true);
>>
>> -    if (devm_gh_rm_register_platform_ops(&pdev->dev, 
>> &qcom_scm_gh_rm_platform_ops))
>> -        dev_warn(__scm->dev, "Gunyah RM platform ops were already 
>> registered\n");
>> -
>>       return 0;
>>   }
>>
>> diff --git a/drivers/virt/gunyah/Kconfig b/drivers/virt/gunyah/Kconfig
>> index bd8e31184962..a9c48d6518f7 100644
>> --- a/drivers/virt/gunyah/Kconfig
>> +++ b/drivers/virt/gunyah/Kconfig
>> @@ -16,6 +16,11 @@ config GUNYAH
>>   config GUNYAH_PLATFORM_HOOKS
>>       tristate
>>
>> +config GUNYAH_QCOM_PLATFORM_HOOKS
>> +    tristate "Gunyah Platform hooks for Qualcomm"
>> +        depends on ARCH_QCOM && QCOM_SCM
>> +    depends on GUNYAH
>> +
>>   config GUNYAH_VCPU
>>       tristate "Runnable Gunyah vCPUs"
>>       depends on GUNYAH
>> diff --git a/drivers/virt/gunyah/Makefile b/drivers/virt/gunyah/Makefile
>> index 7347b1470491..c33f701bb5c8 100644
>> --- a/drivers/virt/gunyah/Makefile
>> +++ b/drivers/virt/gunyah/Makefile
>> @@ -2,6 +2,7 @@
>>
>>   obj-$(CONFIG_GUNYAH) += gunyah.o
>>   obj-$(CONFIG_GUNYAH_PLATFORM_HOOKS) += gunyah_platform_hooks.o
>> +obj-$(CONFIG_GUNYAH_QCOM_PLATFORM_HOOKS) += gunyah_qcom_platform_hooks.o
>>
>>   gunyah_rsc_mgr-y += rsc_mgr.o rsc_mgr_rpc.o vm_mgr.o vm_mgr_mm.o
>>   obj-$(CONFIG_GUNYAH) += gunyah_rsc_mgr.o
>> diff --git a/drivers/virt/gunyah/gunyah_qcom_platform_hooks.c 
>> b/drivers/virt/gunyah/gunyah_qcom_platform_hooks.c
>> new file mode 100644
>> index 000000000000..3332f84134d3
>> --- /dev/null
>> +++ b/drivers/virt/gunyah/gunyah_qcom_platform_hooks.c
>> @@ -0,0 +1,35 @@
>> +#include <linux/kernel.h>
>> +#include <linux/module.h>
>> +#include <linux/firmware/qcom/qcom_scm.h>
>> +#include <linux/gunyah_rsc_mgr.h>
>> +
>> +static int qcom_gh_rm_pre_mem_share(struct gh_rm *rm, struct 
>> gh_rm_mem_parcel *mem_parcel)
>> +{
>> +    return qcom_scm_gh_rm_pre_mem_share(mem_parcel);
>> +}
>> +
>> +static int qcom_gh_rm_post_mem_reclaim(struct gh_rm *rm, struct 
>> gh_rm_mem_parcel *mem_parcel)
>> +{
>> +    return qcom_scm_gh_rm_post_mem_reclaim(mem_parcel);
>> +}
>> +
>> +static struct gh_rm_platform_ops qcom_gh_platform_hooks_ops = {
>> +    .pre_mem_share = qcom_gh_rm_pre_mem_share,
>> +    .post_mem_reclaim = qcom_gh_rm_post_mem_reclaim,
>> +};
>> +
>> +static int __init qcom_gh_platform_hooks_register(void)
>> +{
>> +    return gh_rm_register_platform_ops(&qcom_gh_platform_hooks_ops);
>> +}
>> +
>> +static void __exit qcom_gh_platform_hooks_unregister(void)
>> +{
>> +    gh_rm_unregister_platform_ops(&qcom_gh_platform_hooks_ops);
>> +}
>> +
>> +module_init(qcom_gh_platform_hooks_register);
>> +module_exit(qcom_gh_platform_hooks_unregister);
>> +
>> +MODULE_DESCRIPTION("Qualcomm Technologies, Inc. Gunyah Platform Hooks 
>> driver");
>> +MODULE_LICENSE("GPL v2");
>> diff --git a/include/linux/firmware/qcom/qcom_scm.h 
>> b/include/linux/firmware/qcom/qcom_scm.h
>> index 1e449a5d7f5c..9b0d33db803d 100644
>> --- a/include/linux/firmware/qcom/qcom_scm.h
>> +++ b/include/linux/firmware/qcom/qcom_scm.h
>> @@ -121,5 +121,8 @@ extern int qcom_scm_lmh_dcvsh(u32 payload_fn, u32 
>> payload_reg, u32 payload_val,
>>                     u64 limit_node, u32 node_id, u64 version);
>>   extern int qcom_scm_lmh_profile_change(u32 profile_id);
>>   extern bool qcom_scm_lmh_dcvsh_available(void);
>> +struct gh_rm_mem_parcel;
>> +extern int qcom_scm_gh_rm_post_mem_reclaim(struct gh_rm_mem_parcel 
>> *mem_parcel);
>> +extern int qcom_scm_gh_rm_pre_mem_share(struct gh_rm_mem_parcel 
>> *mem_parcel);
>>
>>   #endif
>> --------------------------->cut<-----------------------
>>
>>>   config QCOM_SCM_DOWNLOAD_MODE_DEFAULT
>>>       bool "Qualcomm download mode enabled by default"
>>> diff --git a/drivers/firmware/qcom_scm.c b/drivers/firmware/qcom_scm.c
>>> index b95616b35bff..89a261a9e021 100644
>>> --- a/drivers/firmware/qcom_scm.c
>>> +++ b/drivers/firmware/qcom_scm.c
>>> @@ -20,6 +20,7 @@
>>>   #include <linux/clk.h>
>>>   #include <linux/reset-controller.h>
>>>   #include <linux/arm-smccc.h>
>>> +#include <linux/gunyah_rsc_mgr.h>
>>>   #include "qcom_scm.h"
>>> @@ -30,6 +31,9 @@ module_param(download_mode, bool, 0);
>>>   #define SCM_HAS_IFACE_CLK    BIT(1)
>>>   #define SCM_HAS_BUS_CLK        BIT(2)
>>> +#define QCOM_SCM_RM_MANAGED_VMID    0x3A
>>> +#define QCOM_SCM_MAX_MANAGED_VMID    0x3F
>>> +
>>>   struct qcom_scm {
>>>       struct device *dev;
>>>       struct clk *core_clk;
>>> @@ -1299,6 +1303,99 @@ int qcom_scm_lmh_dcvsh(u32 payload_fn, u32 
>>> payload_reg, u32 payload_val,
>>>   }
>>>   EXPORT_SYMBOL(qcom_scm_lmh_dcvsh);
>>> +static int qcom_scm_gh_rm_pre_mem_share(struct gh_rm *rm, struct 
>>> gh_rm_mem_parcel *mem_parcel)
>>> +{
>>> +    struct qcom_scm_vmperm *new_perms;
>>> +    u64 src, src_cpy;
>>> +    int ret = 0, i, n;
>>> +    u16 vmid;
>>> +
>>> +    new_perms = kcalloc(mem_parcel->n_acl_entries, 
>>> sizeof(*new_perms), GFP_KERNEL);
>>> +    if (!new_perms)
>>> +        return -ENOMEM;
>>> +
>>> +    for (n = 0; n < mem_parcel->n_acl_entries; n++) {
>>> +        vmid = le16_to_cpu(mem_parcel->acl_entries[n].vmid);
>>> +        if (vmid <= QCOM_SCM_MAX_MANAGED_VMID)
>>> +            new_perms[n].vmid = vmid;
>>> +        else
>>> +            new_perms[n].vmid = QCOM_SCM_RM_MANAGED_VMID;
>>> +        if (mem_parcel->acl_entries[n].perms & GH_RM_ACL_X)
>>> +            new_perms[n].perm |= QCOM_SCM_PERM_EXEC;
>>> +        if (mem_parcel->acl_entries[n].perms & GH_RM_ACL_W)
>>> +            new_perms[n].perm |= QCOM_SCM_PERM_WRITE;
>>> +        if (mem_parcel->acl_entries[n].perms & GH_RM_ACL_R)
>>> +            new_perms[n].perm |= QCOM_SCM_PERM_READ;
>>> +    }
>>> +
>>> +    src = (1ull << QCOM_SCM_VMID_HLOS);
>>> +
>>> +    for (i = 0; i < mem_parcel->n_mem_entries; i++) {
>>> +        src_cpy = src;
>>> +        ret = 
>>> qcom_scm_assign_mem(le64_to_cpu(mem_parcel->mem_entries[i].ipa_base),
>>> +                        le64_to_cpu(mem_parcel->mem_entries[i].size),
>>> +                        &src_cpy, new_perms, 
>>> mem_parcel->n_acl_entries);
>>> +        if (ret) {
>>> +            src = 0;
>>> +            for (n = 0; n < mem_parcel->n_acl_entries; n++) {
>>> +                vmid = le16_to_cpu(mem_parcel->acl_entries[n].vmid);
>>> +                if (vmid <= QCOM_SCM_MAX_MANAGED_VMID)
>>> +                    src |= (1ull << vmid);
>>> +                else
>>> +                    src |= (1ull << QCOM_SCM_RM_MANAGED_VMID);
>>> +            }
>>> +
>>> +            new_perms[0].vmid = QCOM_SCM_VMID_HLOS;
>>> +
>>> +            for (i--; i >= 0; i--) {
>>> +                src_cpy = src;
>>> +                WARN_ON_ONCE(qcom_scm_assign_mem(
>>> + le64_to_cpu(mem_parcel->mem_entries[i].ipa_base),
>>> +                        le64_to_cpu(mem_parcel->mem_entries[i].size),
>>> +                        &src_cpy, new_perms, 1));
>>> +            }
>>> +            break;
>>> +        }
>>> +    }
>>> +
>>> +    kfree(new_perms);
>>> +    return ret;
>>> +}
>>> +
>>> +static int qcom_scm_gh_rm_post_mem_reclaim(struct gh_rm *rm, struct 
>>> gh_rm_mem_parcel *mem_parcel)
>>> +{
>>> +    struct qcom_scm_vmperm new_perms;
>>> +    u64 src = 0, src_cpy;
>>> +    int ret = 0, i, n;
>>> +    u16 vmid;
>>> +
>>> +    new_perms.vmid = QCOM_SCM_VMID_HLOS;
>>> +    new_perms.perm = QCOM_SCM_PERM_EXEC | QCOM_SCM_PERM_WRITE | 
>>> QCOM_SCM_PERM_READ;
>>> +
>>> +    for (n = 0; n < mem_parcel->n_acl_entries; n++) {
>>> +        vmid = le16_to_cpu(mem_parcel->acl_entries[n].vmid);
>>> +        if (vmid <= QCOM_SCM_MAX_MANAGED_VMID)
>>> +            src |= (1ull << vmid);
>>> +        else
>>> +            src |= (1ull << QCOM_SCM_RM_MANAGED_VMID);
>>> +    }
>>> +
>>> +    for (i = 0; i < mem_parcel->n_mem_entries; i++) {
>>> +        src_cpy = src;
>>> +        ret = 
>>> qcom_scm_assign_mem(le64_to_cpu(mem_parcel->mem_entries[i].ipa_base),
>>> +                        le64_to_cpu(mem_parcel->mem_entries[i].size),
>>> +                        &src_cpy, &new_perms, 1);
>>> +        WARN_ON_ONCE(ret);
>>> +    }
>>> +
>>> +    return ret;
>>> +}
>>> +
>>> +static struct gh_rm_platform_ops qcom_scm_gh_rm_platform_ops = {
>>> +    .pre_mem_share = qcom_scm_gh_rm_pre_mem_share,
>>> +    .post_mem_reclaim = qcom_scm_gh_rm_post_mem_reclaim,
>>> +};
>>> +
>>>   static int qcom_scm_find_dload_address(struct device *dev, u64 *addr)
>>>   {
>>>       struct device_node *tcsr;
>>> @@ -1502,6 +1599,9 @@ static int qcom_scm_probe(struct 
>>> platform_device *pdev)
>>>       if (download_mode)
>>>           qcom_scm_set_download_mode(true);
>>> +    if (devm_gh_rm_register_platform_ops(&pdev->dev, 
>>> &qcom_scm_gh_rm_platform_ops))
>>> +        dev_warn(__scm->dev, "Gunyah RM platform ops were already 
>>> registered\n");
>>> +
>>>       return 0;
>>>   }
>>> diff --git a/include/linux/gunyah_rsc_mgr.h 
>>> b/include/linux/gunyah_rsc_mgr.h
>>> index 515087931a2b..acf8c1545a6c 100644
>>> --- a/include/linux/gunyah_rsc_mgr.h
>>> +++ b/include/linux/gunyah_rsc_mgr.h
>>> @@ -145,7 +145,7 @@ int gh_rm_get_hyp_resources(struct gh_rm *rm, u16 
>>> vmid,
>>>                   struct gh_rm_hyp_resources **resources);
>>>   int gh_rm_get_vmid(struct gh_rm *rm, u16 *vmid);
>>> -struct gunyah_rm_platform_ops {
>>> +struct gh_rm_platform_ops {
>>>       int (*pre_mem_share)(struct gh_rm *rm, struct gh_rm_mem_parcel 
>>> *mem_parcel);
>>>       int (*post_mem_reclaim)(struct gh_rm *rm, struct 
>>> gh_rm_mem_parcel *mem_parcel);
>>>   };