On Tue, Jun 13, 2023 at 10:20:42AM -0700, Elliot Berman wrote:
> On Qualcomm platforms, there is a firmware entity which controls access
> to physical pages. In order to share memory with another VM, this entity
> needs to be informed that the guest VM should have access to the memory.
>
Why isn't this handled by the system above us?
> Reviewed-by: Alex Elder <elder@linaro.org>
> 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/virt/gunyah/Kconfig | 4 ++
> drivers/virt/gunyah/Makefile | 2 +
> drivers/virt/gunyah/gunyah_platform_hooks.c | 80 +++++++++++++++++++++
> drivers/virt/gunyah/rsc_mgr.h | 3 +
> drivers/virt/gunyah/rsc_mgr_rpc.c | 18 ++++-
> include/linux/gunyah_rsc_mgr.h | 17 +++++
> 6 files changed, 122 insertions(+), 2 deletions(-)
> create mode 100644 drivers/virt/gunyah/gunyah_platform_hooks.c
>
> diff --git a/drivers/virt/gunyah/Kconfig b/drivers/virt/gunyah/Kconfig
> index 1a737694c333d..de815189dab6c 100644
> --- a/drivers/virt/gunyah/Kconfig
> +++ b/drivers/virt/gunyah/Kconfig
> @@ -4,6 +4,7 @@ config GUNYAH
> tristate "Gunyah Virtualization drivers"
> depends on ARM64
> depends on MAILBOX
> + select GUNYAH_PLATFORM_HOOKS
> help
> The Gunyah drivers are the helper interfaces that run in a guest VM
> such as basic inter-VM IPC and signaling mechanisms, and higher level
> @@ -11,3 +12,6 @@ config GUNYAH
>
> Say Y/M here to enable the drivers needed to interact in a Gunyah
> virtual environment.
> +
> +config GUNYAH_PLATFORM_HOOKS
Automatically selected by GUNYAH and the only platform so far, no need
to keep this as a separate Kconfig.
> + tristate
> diff --git a/drivers/virt/gunyah/Makefile b/drivers/virt/gunyah/Makefile
> index bacf78b8fa337..4fbeee521d60a 100644
> --- a/drivers/virt/gunyah/Makefile
> +++ b/drivers/virt/gunyah/Makefile
> @@ -1,4 +1,6 @@
> # SPDX-License-Identifier: GPL-2.0
>
> +obj-$(CONFIG_GUNYAH_PLATFORM_HOOKS) += gunyah_platform_hooks.o
> +
Why is this added before the core gunyah components?
> gunyah-y += rsc_mgr.o rsc_mgr_rpc.o vm_mgr.o vm_mgr_mm.o
> obj-$(CONFIG_GUNYAH) += gunyah.o
Regards,
Bjorn
@@ -4,6 +4,7 @@ config GUNYAH
tristate "Gunyah Virtualization drivers"
depends on ARM64
depends on MAILBOX
+ select GUNYAH_PLATFORM_HOOKS
help
The Gunyah drivers are the helper interfaces that run in a guest VM
such as basic inter-VM IPC and signaling mechanisms, and higher level
@@ -11,3 +12,6 @@ config GUNYAH
Say Y/M here to enable the drivers needed to interact in a Gunyah
virtual environment.
+
+config GUNYAH_PLATFORM_HOOKS
+ tristate
@@ -1,4 +1,6 @@
# SPDX-License-Identifier: GPL-2.0
+obj-$(CONFIG_GUNYAH_PLATFORM_HOOKS) += gunyah_platform_hooks.o
+
gunyah-y += rsc_mgr.o rsc_mgr_rpc.o vm_mgr.o vm_mgr_mm.o
obj-$(CONFIG_GUNYAH) += gunyah.o
new file mode 100644
@@ -0,0 +1,80 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2022-2023 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#include <linux/module.h>
+#include <linux/rwsem.h>
+#include <linux/gunyah_rsc_mgr.h>
+
+#include "rsc_mgr.h"
+
+static const struct gh_rm_platform_ops *rm_platform_ops;
+static DECLARE_RWSEM(rm_platform_ops_lock);
+
+int gh_rm_platform_pre_mem_share(struct gh_rm *rm, struct gh_rm_mem_parcel *mem_parcel)
+{
+ int ret = 0;
+
+ down_read(&rm_platform_ops_lock);
+ if (rm_platform_ops && rm_platform_ops->pre_mem_share)
+ ret = rm_platform_ops->pre_mem_share(rm, mem_parcel);
+ up_read(&rm_platform_ops_lock);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(gh_rm_platform_pre_mem_share);
+
+int gh_rm_platform_post_mem_reclaim(struct gh_rm *rm, struct gh_rm_mem_parcel *mem_parcel)
+{
+ int ret = 0;
+
+ down_read(&rm_platform_ops_lock);
+ if (rm_platform_ops && rm_platform_ops->post_mem_reclaim)
+ ret = rm_platform_ops->post_mem_reclaim(rm, mem_parcel);
+ up_read(&rm_platform_ops_lock);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(gh_rm_platform_post_mem_reclaim);
+
+int gh_rm_register_platform_ops(const struct gh_rm_platform_ops *platform_ops)
+{
+ int ret = 0;
+
+ down_write(&rm_platform_ops_lock);
+ if (!rm_platform_ops)
+ rm_platform_ops = platform_ops;
+ else
+ ret = -EEXIST;
+ up_write(&rm_platform_ops_lock);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(gh_rm_register_platform_ops);
+
+void gh_rm_unregister_platform_ops(const struct gh_rm_platform_ops *platform_ops)
+{
+ down_write(&rm_platform_ops_lock);
+ if (rm_platform_ops == platform_ops)
+ rm_platform_ops = NULL;
+ up_write(&rm_platform_ops_lock);
+}
+EXPORT_SYMBOL_GPL(gh_rm_unregister_platform_ops);
+
+static void _devm_gh_rm_unregister_platform_ops(void *data)
+{
+ gh_rm_unregister_platform_ops((const struct gh_rm_platform_ops *)data);
+}
+
+int devm_gh_rm_register_platform_ops(struct device *dev, const struct gh_rm_platform_ops *ops)
+{
+ int ret;
+
+ ret = gh_rm_register_platform_ops(ops);
+ if (ret)
+ return ret;
+
+ return devm_add_action(dev, _devm_gh_rm_unregister_platform_ops, (void *)ops);
+}
+EXPORT_SYMBOL_GPL(devm_gh_rm_register_platform_ops);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Gunyah Platform Hooks");
@@ -13,4 +13,7 @@ struct gh_rm;
int gh_rm_call(struct gh_rm *rsc_mgr, u32 message_id, const void *req_buf, size_t req_buf_size,
void **resp_buf, size_t *resp_buf_size);
+int gh_rm_platform_pre_mem_share(struct gh_rm *rm, struct gh_rm_mem_parcel *mem_parcel);
+int gh_rm_platform_post_mem_reclaim(struct gh_rm *rm, struct gh_rm_mem_parcel *mem_parcel);
+
#endif
@@ -207,6 +207,12 @@ static int gh_rm_mem_lend_common(struct gh_rm *rm, u32 message_id, struct gh_rm_
if (!msg)
return -ENOMEM;
+ ret = gh_rm_platform_pre_mem_share(rm, p);
+ if (ret) {
+ kfree(msg);
+ return ret;
+ }
+
req_header = msg;
acl_section = (void *)req_header + sizeof(*req_header);
mem_section = (void *)acl_section + acl_section_size;
@@ -231,8 +237,10 @@ static int gh_rm_mem_lend_common(struct gh_rm *rm, u32 message_id, struct gh_rm_
ret = gh_rm_call(rm, message_id, msg, msg_size, (void **)&resp, &resp_size);
kfree(msg);
- if (ret)
+ if (ret) {
+ gh_rm_platform_post_mem_reclaim(rm, p);
return ret;
+ }
p->mem_handle = le32_to_cpu(*resp);
kfree(resp);
@@ -287,8 +295,14 @@ int gh_rm_mem_reclaim(struct gh_rm *rm, struct gh_rm_mem_parcel *parcel)
struct gh_rm_mem_release_req req = {
.mem_handle = cpu_to_le32(parcel->mem_handle),
};
+ int ret;
+
+ ret = gh_rm_call(rm, GH_RM_RPC_MEM_RECLAIM, &req, sizeof(req), NULL, NULL);
+ /* Only call the platform mem reclaim hooks if we reclaimed the memory */
+ if (ret)
+ return ret;
- return gh_rm_call(rm, GH_RM_RPC_MEM_RECLAIM, &req, sizeof(req), NULL, NULL);
+ return gh_rm_platform_post_mem_reclaim(rm, parcel);
}
/**
@@ -139,4 +139,21 @@ 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 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);
+};
+
+#if IS_ENABLED(CONFIG_GUNYAH_PLATFORM_HOOKS)
+int gh_rm_register_platform_ops(const struct gh_rm_platform_ops *platform_ops);
+void gh_rm_unregister_platform_ops(const struct gh_rm_platform_ops *platform_ops);
+int devm_gh_rm_register_platform_ops(struct device *dev, const struct gh_rm_platform_ops *ops);
+#else
+static inline int gh_rm_register_platform_ops(const struct gh_rm_platform_ops *platform_ops)
+ { return 0; }
+static inline void gh_rm_unregister_platform_ops(const struct gh_rm_platform_ops *platform_ops) { }
+static inline int devm_gh_rm_register_platform_ops(struct device *dev,
+ const struct gh_rm_platform_ops *ops) { return 0; }
+#endif
+
#endif