Re: [PATCH v11 16/26] firmware: qcom_scm: Register Gunyah platform ops

From: Elliot Berman
Date: Tue Mar 21 2023 - 14:41:06 EST




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@xxxxxxxxxxx>
Signed-off-by: Prakruthi Deepak Heragu <quic_pheragu@xxxxxxxxxxx>
Signed-off-by: Elliot Berman <quic_eberman@xxxxxxxxxxx>
---
  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.

>----------------------->cut<-------------------------------
From 1fb7995aecf17caefd09ffb516579bc4ac9ac301 Mon Sep 17 00:00:00 2001
From: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
Date: Tue, 21 Mar 2023 13:34:02 +0000
Subject: [PATCH] virt: gunyah: add qcom platform hooks

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
---
 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);
  };