diff mbox series

[v9,04/27] virt: gunyah: Add hypercalls to identify Gunyah

Message ID 20230120224627.4053418-5-quic_eberman@quicinc.com (mailing list archive)
State Superseded
Headers show
Series Drivers for gunyah hypervisor | expand

Commit Message

Elliot Berman Jan. 20, 2023, 10:46 p.m. UTC 
Add hypercalls to identify when Linux is running a virtual machine under
Gunyah.

There are two calls to help identify Gunyah:

1. gh_hypercall_get_uid() returns a UID when running under a Gunyah
   hypervisor.
2. gh_hypercall_hyp_identify() returns build information and a set of
   feature flags that are supported by Gunyah.

Signed-off-by: Elliot Berman <quic_eberman@quicinc.com>
---
 MAINTAINERS                          |  2 +
 arch/arm64/Kbuild                    |  1 +
 arch/arm64/gunyah/Makefile           |  3 ++
 arch/arm64/gunyah/gunyah_hypercall.c | 75 ++++++++++++++++++++++++++++
 drivers/virt/Kconfig                 |  2 +
 drivers/virt/gunyah/Kconfig          | 14 ++++++
 include/linux/gunyah.h               | 33 ++++++++++++
 7 files changed, 130 insertions(+)
 create mode 100644 arch/arm64/gunyah/Makefile
 create mode 100644 arch/arm64/gunyah/gunyah_hypercall.c
 create mode 100644 drivers/virt/gunyah/Kconfig

Comments

Greg KH Jan. 30, 2023, 10:01 a.m. UTC | #1 
On Fri, Jan 20, 2023 at 02:46:03PM -0800, Elliot Berman wrote:
> Add hypercalls to identify when Linux is running a virtual machine under
> Gunyah.
> 
> There are two calls to help identify Gunyah:
> 
> 1. gh_hypercall_get_uid() returns a UID when running under a Gunyah
>    hypervisor.
> 2. gh_hypercall_hyp_identify() returns build information and a set of
>    feature flags that are supported by Gunyah.
> 
> Signed-off-by: Elliot Berman <quic_eberman@quicinc.com>
> ---
>  MAINTAINERS                          |  2 +
>  arch/arm64/Kbuild                    |  1 +
>  arch/arm64/gunyah/Makefile           |  3 ++
>  arch/arm64/gunyah/gunyah_hypercall.c | 75 ++++++++++++++++++++++++++++
>  drivers/virt/Kconfig                 |  2 +
>  drivers/virt/gunyah/Kconfig          | 14 ++++++
>  include/linux/gunyah.h               | 33 ++++++++++++
>  7 files changed, 130 insertions(+)
>  create mode 100644 arch/arm64/gunyah/Makefile
>  create mode 100644 arch/arm64/gunyah/gunyah_hypercall.c
>  create mode 100644 drivers/virt/gunyah/Kconfig
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index f1e07e39b2f5..fe19e71efc6d 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -9048,6 +9048,8 @@ L:	linux-arm-msm@vger.kernel.org
>  S:	Supported
>  F:	Documentation/devicetree/bindings/firmware/gunyah-hypervisor.yaml
>  F:	Documentation/virt/gunyah/
> +F:	arch/arm64/gunyah/
> +F:	drivers/virt/gunyah/
>  F:	include/linux/gunyah.h
>  
>  HABANALABS PCI DRIVER
> diff --git a/arch/arm64/Kbuild b/arch/arm64/Kbuild
> index 5bfbf7d79c99..e4847ba0e3c9 100644
> --- a/arch/arm64/Kbuild
> +++ b/arch/arm64/Kbuild
> @@ -3,6 +3,7 @@ obj-y			+= kernel/ mm/ net/
>  obj-$(CONFIG_KVM)	+= kvm/
>  obj-$(CONFIG_XEN)	+= xen/
>  obj-$(subst m,y,$(CONFIG_HYPERV))	+= hyperv/
> +obj-$(CONFIG_GUNYAH)	+= gunyah/
>  obj-$(CONFIG_CRYPTO)	+= crypto/
>  
>  # for cleaning
> diff --git a/arch/arm64/gunyah/Makefile b/arch/arm64/gunyah/Makefile
> new file mode 100644
> index 000000000000..84f1e38cafb1
> --- /dev/null
> +++ b/arch/arm64/gunyah/Makefile
> @@ -0,0 +1,3 @@
> +# SPDX-License-Identifier: GPL-2.0
> +
> +obj-$(CONFIG_GUNYAH) += gunyah_hypercall.o
> diff --git a/arch/arm64/gunyah/gunyah_hypercall.c b/arch/arm64/gunyah/gunyah_hypercall.c
> new file mode 100644
> index 000000000000..ffed4b71641f
> --- /dev/null
> +++ b/arch/arm64/gunyah/gunyah_hypercall.c
> @@ -0,0 +1,75 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) 2022-2023 Qualcomm Innovation Center, Inc. All rights reserved.
> + */
> +
> +#include <linux/arm-smccc.h>
> +#include <linux/module.h>
> +#include <linux/gunyah.h>
> +
> +static const uint32_t gunyah_known_uuids[][4] = {

uint32_t is not a kernel type, please use sane ones, like u32.

> +	{0x19bd54bd, 0x0b37571b, 0x946f609b, 0x54539de6}, /* QC_HYP (Qualcomm's build) */
> +	{0x673d5f14, 0x9265ce36, 0xa4535fdb, 0xc1d58fcd}, /* GUNYAH (open source build) */

And why not use the kernel uuid type here?  Why create your own?

> +};
> +
> +#define GH_HYPERCALL_HYP_IDENTIFY		GH_HYPERCALL(0x0000)
> +
> +/**
> + * gh_hypercall_get_uid() - Returns a UID when running under a Gunyah hypervisor
> + * @uid: An array of 4 u32's (u32 uid[4];)
> + *
> + * Caller should compare the resulting UID to a list of known Gunyah UIDs to
> + * confirm that Linux is running as a guest of Gunyah.
> + */
> +void gh_hypercall_get_uid(u32 uid[4])
> +{
> +	struct arm_smccc_res res;
> +	u32 uid[4];

How does this work when you have a local variable the same name as the
parameter to the function?  What shadows what and how?  The compiler
didn't complain about this?

> +	int i;
> +
> +	arm_smccc_1_1_hvc(ARM_SMCCC_VENDOR_HYP_CALL_UID_FUNC_ID, &res);
> +
> +	uid[0] = lower_32_bits(res.a0);
> +	uid[1] = lower_32_bits(res.a1);
> +	uid[2] = lower_32_bits(res.a2);
> +	uid[3] = lower_32_bits(res.a3);
> +
> +	for (i = 0; i < ARRAY_SIZE(gunyah_known_uuids); i++)
> +		if (!memcmp(uid, gunyah_known_uuids[i], sizeof(uid)))
> +			break;
> +
> +	return i != ARRAY_SIZE(gunyah_known_uuids);

How can a function that returns void actually return anything?

This obviously was never compiled.  I'm stopping here in my review.

greg k-h
Elliot Berman Jan. 30, 2023, 7:05 p.m. UTC | #2 
On 1/30/2023 2:01 AM, Greg Kroah-Hartman wrote:
> On Fri, Jan 20, 2023 at 02:46:03PM -0800, Elliot Berman wrote:
>> Add hypercalls to identify when Linux is running a virtual machine under
>> Gunyah.
>>
>> There are two calls to help identify Gunyah:
>>
>> 1. gh_hypercall_get_uid() returns a UID when running under a Gunyah
>>     hypervisor.
>> 2. gh_hypercall_hyp_identify() returns build information and a set of
>>     feature flags that are supported by Gunyah.
>>
>> Signed-off-by: Elliot Berman <quic_eberman@quicinc.com>
>> ---
>>   MAINTAINERS                          |  2 +
>>   arch/arm64/Kbuild                    |  1 +
>>   arch/arm64/gunyah/Makefile           |  3 ++
>>   arch/arm64/gunyah/gunyah_hypercall.c | 75 ++++++++++++++++++++++++++++
>>   drivers/virt/Kconfig                 |  2 +
>>   drivers/virt/gunyah/Kconfig          | 14 ++++++
>>   include/linux/gunyah.h               | 33 ++++++++++++
>>   7 files changed, 130 insertions(+)
>>   create mode 100644 arch/arm64/gunyah/Makefile
>>   create mode 100644 arch/arm64/gunyah/gunyah_hypercall.c
>>   create mode 100644 drivers/virt/gunyah/Kconfig
>>
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index f1e07e39b2f5..fe19e71efc6d 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -9048,6 +9048,8 @@ L:	linux-arm-msm@vger.kernel.org
>>   S:	Supported
>>   F:	Documentation/devicetree/bindings/firmware/gunyah-hypervisor.yaml
>>   F:	Documentation/virt/gunyah/
>> +F:	arch/arm64/gunyah/
>> +F:	drivers/virt/gunyah/
>>   F:	include/linux/gunyah.h
>>   
>>   HABANALABS PCI DRIVER
>> diff --git a/arch/arm64/Kbuild b/arch/arm64/Kbuild
>> index 5bfbf7d79c99..e4847ba0e3c9 100644
>> --- a/arch/arm64/Kbuild
>> +++ b/arch/arm64/Kbuild
>> @@ -3,6 +3,7 @@ obj-y			+= kernel/ mm/ net/
>>   obj-$(CONFIG_KVM)	+= kvm/
>>   obj-$(CONFIG_XEN)	+= xen/
>>   obj-$(subst m,y,$(CONFIG_HYPERV))	+= hyperv/
>> +obj-$(CONFIG_GUNYAH)	+= gunyah/
>>   obj-$(CONFIG_CRYPTO)	+= crypto/
>>   
>>   # for cleaning
>> diff --git a/arch/arm64/gunyah/Makefile b/arch/arm64/gunyah/Makefile
>> new file mode 100644
>> index 000000000000..84f1e38cafb1
>> --- /dev/null
>> +++ b/arch/arm64/gunyah/Makefile
>> @@ -0,0 +1,3 @@
>> +# SPDX-License-Identifier: GPL-2.0
>> +
>> +obj-$(CONFIG_GUNYAH) += gunyah_hypercall.o
>> diff --git a/arch/arm64/gunyah/gunyah_hypercall.c b/arch/arm64/gunyah/gunyah_hypercall.c
>> new file mode 100644
>> index 000000000000..ffed4b71641f
>> --- /dev/null
>> +++ b/arch/arm64/gunyah/gunyah_hypercall.c
>> @@ -0,0 +1,75 @@
>> +// SPDX-License-Identifier: GPL-2.0-only
>> +/*
>> + * Copyright (c) 2022-2023 Qualcomm Innovation Center, Inc. All rights reserved.
>> + */
>> +
>> +#include <linux/arm-smccc.h>
>> +#include <linux/module.h>
>> +#include <linux/gunyah.h>
>> +
>> +static const uint32_t gunyah_known_uuids[][4] = {
> 
> uint32_t is not a kernel type, please use sane ones, like u32.
> 
>> +	{0x19bd54bd, 0x0b37571b, 0x946f609b, 0x54539de6}, /* QC_HYP (Qualcomm's build) */
>> +	{0x673d5f14, 0x9265ce36, 0xa4535fdb, 0xc1d58fcd}, /* GUNYAH (open source build) */
> 
> And why not use the kernel uuid type here?  Why create your own?
> 
>> +};
>> +
>> +#define GH_HYPERCALL_HYP_IDENTIFY		GH_HYPERCALL(0x0000)
>> +
>> +/**
>> + * gh_hypercall_get_uid() - Returns a UID when running under a Gunyah hypervisor
>> + * @uid: An array of 4 u32's (u32 uid[4];)
>> + *
>> + * Caller should compare the resulting UID to a list of known Gunyah UIDs to
>> + * confirm that Linux is running as a guest of Gunyah.
>> + */
>> +void gh_hypercall_get_uid(u32 uid[4])
>> +{
>> +	struct arm_smccc_res res;
>> +	u32 uid[4];
> 
> How does this work when you have a local variable the same name as the
> parameter to the function?  What shadows what and how?  The compiler
> didn't complain about this?
> 
>> +	int i;
>> +
>> +	arm_smccc_1_1_hvc(ARM_SMCCC_VENDOR_HYP_CALL_UID_FUNC_ID, &res);
>> +
>> +	uid[0] = lower_32_bits(res.a0);
>> +	uid[1] = lower_32_bits(res.a1);
>> +	uid[2] = lower_32_bits(res.a2);
>> +	uid[3] = lower_32_bits(res.a3);
>> +
>> +	for (i = 0; i < ARRAY_SIZE(gunyah_known_uuids); i++)
>> +		if (!memcmp(uid, gunyah_known_uuids[i], sizeof(uid)))
>> +			break;
>> +
>> +	return i != ARRAY_SIZE(gunyah_known_uuids);
> 
> How can a function that returns void actually return anything?
> 
> This obviously was never compiled.  I'm stopping here in my review.
> 

Fell victim to trusting automatic git commit --fixup tools here. I'll 
send out v10 with proper bisectability.
diff mbox series

Patch

diff --git a/MAINTAINERS b/MAINTAINERS
index f1e07e39b2f5..fe19e71efc6d 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -9048,6 +9048,8 @@  L:	linux-arm-msm@vger.kernel.org
 S:	Supported
 F:	Documentation/devicetree/bindings/firmware/gunyah-hypervisor.yaml
 F:	Documentation/virt/gunyah/
+F:	arch/arm64/gunyah/
+F:	drivers/virt/gunyah/
 F:	include/linux/gunyah.h
 
 HABANALABS PCI DRIVER
diff --git a/arch/arm64/Kbuild b/arch/arm64/Kbuild
index 5bfbf7d79c99..e4847ba0e3c9 100644
--- a/arch/arm64/Kbuild
+++ b/arch/arm64/Kbuild
@@ -3,6 +3,7 @@  obj-y			+= kernel/ mm/ net/
 obj-$(CONFIG_KVM)	+= kvm/
 obj-$(CONFIG_XEN)	+= xen/
 obj-$(subst m,y,$(CONFIG_HYPERV))	+= hyperv/
+obj-$(CONFIG_GUNYAH)	+= gunyah/
 obj-$(CONFIG_CRYPTO)	+= crypto/
 
 # for cleaning
diff --git a/arch/arm64/gunyah/Makefile b/arch/arm64/gunyah/Makefile
new file mode 100644
index 000000000000..84f1e38cafb1
--- /dev/null
+++ b/arch/arm64/gunyah/Makefile
@@ -0,0 +1,3 @@ 
+# SPDX-License-Identifier: GPL-2.0
+
+obj-$(CONFIG_GUNYAH) += gunyah_hypercall.o
diff --git a/arch/arm64/gunyah/gunyah_hypercall.c b/arch/arm64/gunyah/gunyah_hypercall.c
new file mode 100644
index 000000000000..ffed4b71641f
--- /dev/null
+++ b/arch/arm64/gunyah/gunyah_hypercall.c
@@ -0,0 +1,75 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2022-2023 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#include <linux/arm-smccc.h>
+#include <linux/module.h>
+#include <linux/gunyah.h>
+
+static const uint32_t gunyah_known_uuids[][4] = {
+	{0x19bd54bd, 0x0b37571b, 0x946f609b, 0x54539de6}, /* QC_HYP (Qualcomm's build) */
+	{0x673d5f14, 0x9265ce36, 0xa4535fdb, 0xc1d58fcd}, /* GUNYAH (open source build) */
+};
+
+#define GH_HYPERCALL_HYP_IDENTIFY		GH_HYPERCALL(0x0000)
+
+/**
+ * gh_hypercall_get_uid() - Returns a UID when running under a Gunyah hypervisor
+ * @uid: An array of 4 u32's (u32 uid[4];)
+ *
+ * Caller should compare the resulting UID to a list of known Gunyah UIDs to
+ * confirm that Linux is running as a guest of Gunyah.
+ */
+void gh_hypercall_get_uid(u32 uid[4])
+{
+	struct arm_smccc_res res;
+	u32 uid[4];
+	int i;
+
+	arm_smccc_1_1_hvc(ARM_SMCCC_VENDOR_HYP_CALL_UID_FUNC_ID, &res);
+
+	uid[0] = lower_32_bits(res.a0);
+	uid[1] = lower_32_bits(res.a1);
+	uid[2] = lower_32_bits(res.a2);
+	uid[3] = lower_32_bits(res.a3);
+
+	for (i = 0; i < ARRAY_SIZE(gunyah_known_uuids); i++)
+		if (!memcmp(uid, gunyah_known_uuids[i], sizeof(uid)))
+			break;
+
+	return i != ARRAY_SIZE(gunyah_known_uuids);
+}
+EXPORT_SYMBOL_GPL(arch_is_gunyah_guest);
+
+#define GH_HYPERCALL(fn)	ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, ARM_SMCCC_SMC_64, \
+						   ARM_SMCCC_OWNER_VENDOR_HYP, \
+						   fn)
+
+#define GH_HYPERCALL_HYP_IDENTIFY		GH_HYPERCALL(0x8000)
+#define GH_HYPERCALL_DBL_SEND			GH_HYPERCALL(0x8012)
+#define GH_HYPERCALL_DBL_SET_MASK		GH_HYPERCALL(0x8015)
+#define GH_HYPERCALL_MSGQ_SEND			GH_HYPERCALL(0x801B)
+#define GH_HYPERCALL_MSGQ_RECV			GH_HYPERCALL(0x801C)
+#define GH_HYPERCALL_VCPU_RUN			GH_HYPERCALL(0x8065)
+
+/**
+ * gh_hypercall_hyp_identify() - Returns build information and feature flags
+ *                               supported by Gunyah.
+ * @hyp_identity: filled by the hypercall with the API info and feature flags.
+ */
+void gh_hypercall_hyp_identify(struct gh_hypercall_hyp_identify_resp *hyp_identity)
+{
+	struct arm_smccc_res res;
+
+	arm_smccc_1_1_hvc(GH_HYPERCALL_HYP_IDENTIFY, &res);
+
+	hyp_identity->api_info = res.a0;
+	hyp_identity->flags[0] = res.a1;
+	hyp_identity->flags[1] = res.a2;
+	hyp_identity->flags[2] = res.a3;
+}
+EXPORT_SYMBOL_GPL(gh_hypercall_hyp_identify);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Gunyah Hypervisor Hypercalls");
diff --git a/drivers/virt/Kconfig b/drivers/virt/Kconfig
index f79ab13a5c28..85bd6626ffc9 100644
--- a/drivers/virt/Kconfig
+++ b/drivers/virt/Kconfig
@@ -54,4 +54,6 @@  source "drivers/virt/coco/sev-guest/Kconfig"
 
 source "drivers/virt/coco/tdx-guest/Kconfig"
 
+source "drivers/virt/gunyah/Kconfig"
+
 endif
diff --git a/drivers/virt/gunyah/Kconfig b/drivers/virt/gunyah/Kconfig
new file mode 100644
index 000000000000..71c38845bcea
--- /dev/null
+++ b/drivers/virt/gunyah/Kconfig
@@ -0,0 +1,14 @@ 
+# SPDX-License-Identifier: GPL-2.0-only
+
+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
+	  services such as memory/device sharing, IRQ sharing, and so on.
+
+	  Say Y/M here to enable the drivers needed to interact in a Gunyah
+	  virtual environment.
diff --git a/include/linux/gunyah.h b/include/linux/gunyah.h
index 985c6086348e..6724d1264d58 100644
--- a/include/linux/gunyah.h
+++ b/include/linux/gunyah.h
@@ -6,8 +6,10 @@ 
 #ifndef _LINUX_GUNYAH_H
 #define _LINUX_GUNYAH_H
 
+#include <linux/bitfield.h>
 #include <linux/errno.h>
 #include <linux/limits.h>
+#include <linux/types.h>
 
 /* Common Gunyah macros */
 #define GH_CAPID_INVAL	U64_MAX
@@ -71,4 +73,35 @@  static inline int gh_remap_error(int gh_error)
 	}
 }
 
+enum gh_api_feature {
+	GH_API_FEATURE_DOORBELL,
+	GH_API_FEATURE_MSGQUEUE,
+	GH_API_FEATURE_VCPU,
+	GH_API_FEATURE_MEMEXTENT,
+};
+
+bool arch_is_gunyah_guest(void);
+
+u16 gh_api_version(void);
+bool gh_api_has_feature(enum gh_api_feature feature);
+
+#define GUNYAH_API_V1			1
+
+#define GH_API_INFO_API_VERSION_MASK	GENMASK_ULL(13, 0)
+#define GH_API_INFO_BIG_ENDIAN		BIT_ULL(14)
+#define GH_API_INFO_IS_64BIT		BIT_ULL(15)
+#define GH_API_INFO_VARIANT_MASK	GENMASK_ULL(63, 56)
+
+#define GH_IDENTIFY_DOORBELL			BIT_ULL(1)
+#define GH_IDENTIFY_MSGQUEUE			BIT_ULL(2)
+#define GH_IDENTIFY_VCPU			BIT_ULL(5)
+#define GH_IDENTIFY_MEMEXTENT			BIT_ULL(6)
+
+struct gh_hypercall_hyp_identify_resp {
+	u64 api_info;
+	u64 flags[3];
+};
+
+void gh_hypercall_hyp_identify(struct gh_hypercall_hyp_identify_resp *hyp_identity);
+
 #endif