[PATCH] Drivers: hv: ioctl for self targeted passthrough hvcalls

[PATCH] Drivers: hv: ioctl for self targeted passthrough hvcalls

[Anirudh Rayabharam]

From: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com>

Allow MSHV_ROOT_HVCALL IOCTL on the /dev/mshv fd. This IOCTL would
execute a passthrough hypercall targeting the root/parent partition
i.e. HV_PARTITION_ID_SELF.

This will be useful for the VMM to query things like supported
synthetic processor features, supported VMM capabiliites etc.

While at it, add HVCALL_GET_PARTITION_PROPERTY_EX to the allowed list of
passthrough hypercalls.

Signed-off-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com>
---
 drivers/hv/mshv_root_main.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/hv/mshv_root_main.c b/drivers/hv/mshv_root_main.c
index 20eda00a1b5a..98f56322cd19 100644
--- a/drivers/hv/mshv_root_main.c
+++ b/drivers/hv/mshv_root_main.c
@@ -122,6 +122,7 @@ static struct miscdevice mshv_dev = {
  */
 static u16 mshv_passthru_hvcalls[] = {
 	HVCALL_GET_PARTITION_PROPERTY,
+	HVCALL_GET_PARTITION_PROPERTY_EX,
 	HVCALL_SET_PARTITION_PROPERTY,
 	HVCALL_INSTALL_INTERCEPT,
 	HVCALL_GET_VP_REGISTERS,
@@ -159,6 +160,7 @@ static int mshv_ioctl_passthru_hvcall(struct mshv_partition *partition,
 	unsigned int pages_order;
 	void *input_pg = NULL;
 	void *output_pg = NULL;
+	u64 pt_id = partition ? partition->pt_id : HV_PARTITION_ID_SELF;
 
 	if (copy_from_user(&args, user_args, sizeof(args)))
 		return -EFAULT;
@@ -180,7 +182,7 @@ static int mshv_ioctl_passthru_hvcall(struct mshv_partition *partition,
 	is_async = mshv_hvcall_is_async(args.code);
 	if (is_async) {
 		/* async hypercalls can only be called from partition fd */
-		if (!partition_locked)
+		if (!partition || !partition_locked)
 			return -EINVAL;
 		ret = mshv_init_async_handler(partition);
 		if (ret)
@@ -208,7 +210,7 @@ static int mshv_ioctl_passthru_hvcall(struct mshv_partition *partition,
 	 * NOTE: This only works because all the allowed hypercalls' input
 	 * structs begin with a u64 partition_id field.
 	 */
-	*(u64 *)input_pg = partition->pt_id;
+	*(u64 *)input_pg = pt_id;
 
 	if (args.reps)
 		status = hv_do_rep_hypercall(args.code, args.reps, 0,
@@ -226,7 +228,7 @@ static int mshv_ioctl_passthru_hvcall(struct mshv_partition *partition,
 	}
 
 	if (hv_result(status) == HV_STATUS_INSUFFICIENT_MEMORY) {
-		ret = hv_call_deposit_pages(NUMA_NO_NODE, partition->pt_id, 1);
+		ret = hv_call_deposit_pages(NUMA_NO_NODE, pt_id, 1);
 		if (!ret)
 			ret = -EAGAIN;
 	} else if (!hv_result_success(status)) {
@@ -2048,6 +2050,9 @@ static long mshv_dev_ioctl(struct file *filp, unsigned int ioctl,
 	case MSHV_CREATE_PARTITION:
 		return mshv_ioctl_create_partition((void __user *)arg,
 						misc->this_device);
+	case MSHV_ROOT_HVCALL:
+		return mshv_ioctl_passthru_hvcall(NULL, false,
+					(void __user *)arg);
 	}
 
 	return -ENOTTY;
-- 
2.34.1

Re: [PATCH] Drivers: hv: ioctl for self targeted passthrough hvcalls

[Wei Liu]

On Fri, Nov 14, 2025 at 09:58:52AM +0000, Anirudh Rayabharam wrote:
> From: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com>
> 
> Allow MSHV_ROOT_HVCALL IOCTL on the /dev/mshv fd. This IOCTL would
> execute a passthrough hypercall targeting the root/parent partition
> i.e. HV_PARTITION_ID_SELF.
> 
> This will be useful for the VMM to query things like supported
> synthetic processor features, supported VMM capabiliites etc.
> 
> While at it, add HVCALL_GET_PARTITION_PROPERTY_EX to the allowed list of
> passthrough hypercalls.
> 
> Signed-off-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com>

This doesn't apply to hyperv-next. What's its base?

Wei

> ---
>  drivers/hv/mshv_root_main.c | 11 ++++++++---
>  1 file changed, 8 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/hv/mshv_root_main.c b/drivers/hv/mshv_root_main.c
> index 20eda00a1b5a..98f56322cd19 100644
> --- a/drivers/hv/mshv_root_main.c
> +++ b/drivers/hv/mshv_root_main.c
> @@ -122,6 +122,7 @@ static struct miscdevice mshv_dev = {
>   */
>  static u16 mshv_passthru_hvcalls[] = {
>  	HVCALL_GET_PARTITION_PROPERTY,
> +	HVCALL_GET_PARTITION_PROPERTY_EX,
>  	HVCALL_SET_PARTITION_PROPERTY,
>  	HVCALL_INSTALL_INTERCEPT,
>  	HVCALL_GET_VP_REGISTERS,
> @@ -159,6 +160,7 @@ static int mshv_ioctl_passthru_hvcall(struct mshv_partition *partition,
>  	unsigned int pages_order;
>  	void *input_pg = NULL;
>  	void *output_pg = NULL;
> +	u64 pt_id = partition ? partition->pt_id : HV_PARTITION_ID_SELF;
>  
>  	if (copy_from_user(&args, user_args, sizeof(args)))
>  		return -EFAULT;
> @@ -180,7 +182,7 @@ static int mshv_ioctl_passthru_hvcall(struct mshv_partition *partition,
>  	is_async = mshv_hvcall_is_async(args.code);
>  	if (is_async) {
>  		/* async hypercalls can only be called from partition fd */
> -		if (!partition_locked)
> +		if (!partition || !partition_locked)
>  			return -EINVAL;
>  		ret = mshv_init_async_handler(partition);
>  		if (ret)
> @@ -208,7 +210,7 @@ static int mshv_ioctl_passthru_hvcall(struct mshv_partition *partition,
>  	 * NOTE: This only works because all the allowed hypercalls' input
>  	 * structs begin with a u64 partition_id field.
>  	 */
> -	*(u64 *)input_pg = partition->pt_id;
> +	*(u64 *)input_pg = pt_id;
>  
>  	if (args.reps)
>  		status = hv_do_rep_hypercall(args.code, args.reps, 0,
> @@ -226,7 +228,7 @@ static int mshv_ioctl_passthru_hvcall(struct mshv_partition *partition,
>  	}
>  
>  	if (hv_result(status) == HV_STATUS_INSUFFICIENT_MEMORY) {
> -		ret = hv_call_deposit_pages(NUMA_NO_NODE, partition->pt_id, 1);
> +		ret = hv_call_deposit_pages(NUMA_NO_NODE, pt_id, 1);
>  		if (!ret)
>  			ret = -EAGAIN;
>  	} else if (!hv_result_success(status)) {
> @@ -2048,6 +2050,9 @@ static long mshv_dev_ioctl(struct file *filp, unsigned int ioctl,
>  	case MSHV_CREATE_PARTITION:
>  		return mshv_ioctl_create_partition((void __user *)arg,
>  						misc->this_device);
> +	case MSHV_ROOT_HVCALL:
> +		return mshv_ioctl_passthru_hvcall(NULL, false,
> +					(void __user *)arg);
>  	}
>  
>  	return -ENOTTY;
> -- 
> 2.34.1
> 

Re: [PATCH] Drivers: hv: ioctl for self targeted passthrough hvcalls

[Anirudh Rayabharam]

On Sat, Nov 15, 2025 at 06:22:40AM +0000, Wei Liu wrote:
> On Fri, Nov 14, 2025 at 09:58:52AM +0000, Anirudh Rayabharam wrote:
> > From: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com>
> > 
> > Allow MSHV_ROOT_HVCALL IOCTL on the /dev/mshv fd. This IOCTL would
> > execute a passthrough hypercall targeting the root/parent partition
> > i.e. HV_PARTITION_ID_SELF.
> > 
> > This will be useful for the VMM to query things like supported
> > synthetic processor features, supported VMM capabiliites etc.
> > 
> > While at it, add HVCALL_GET_PARTITION_PROPERTY_EX to the allowed list of
> > passthrough hypercalls.
> > 
> > Signed-off-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com>
> 
> This doesn't apply to hyperv-next. What's its base?

Hmmm... I remember doing this on hyperv-next. This the parent I see:

commit f2329fd987a0da4759c307c46fd27c4d05bb7433
Author: Naman Jain <namjain@linux.microsoft.com>
Date:   Thu Nov 13 04:41:49 2025 +0000

    Drivers: hv: Introduce mshv_vtl driver

No worries, I can rebase it on hyperv-next and send it again.

Thanks,
Anirudh.

> 
> Wei
> 
> > ---
> >  drivers/hv/mshv_root_main.c | 11 ++++++++---
> >  1 file changed, 8 insertions(+), 3 deletions(-)
> > 
> > diff --git a/drivers/hv/mshv_root_main.c b/drivers/hv/mshv_root_main.c
> > index 20eda00a1b5a..98f56322cd19 100644
> > --- a/drivers/hv/mshv_root_main.c
> > +++ b/drivers/hv/mshv_root_main.c
> > @@ -122,6 +122,7 @@ static struct miscdevice mshv_dev = {
> >   */
> >  static u16 mshv_passthru_hvcalls[] = {
> >  	HVCALL_GET_PARTITION_PROPERTY,
> > +	HVCALL_GET_PARTITION_PROPERTY_EX,
> >  	HVCALL_SET_PARTITION_PROPERTY,
> >  	HVCALL_INSTALL_INTERCEPT,
> >  	HVCALL_GET_VP_REGISTERS,
> > @@ -159,6 +160,7 @@ static int mshv_ioctl_passthru_hvcall(struct mshv_partition *partition,
> >  	unsigned int pages_order;
> >  	void *input_pg = NULL;
> >  	void *output_pg = NULL;
> > +	u64 pt_id = partition ? partition->pt_id : HV_PARTITION_ID_SELF;
> >  
> >  	if (copy_from_user(&args, user_args, sizeof(args)))
> >  		return -EFAULT;
> > @@ -180,7 +182,7 @@ static int mshv_ioctl_passthru_hvcall(struct mshv_partition *partition,
> >  	is_async = mshv_hvcall_is_async(args.code);
> >  	if (is_async) {
> >  		/* async hypercalls can only be called from partition fd */
> > -		if (!partition_locked)
> > +		if (!partition || !partition_locked)
> >  			return -EINVAL;
> >  		ret = mshv_init_async_handler(partition);
> >  		if (ret)
> > @@ -208,7 +210,7 @@ static int mshv_ioctl_passthru_hvcall(struct mshv_partition *partition,
> >  	 * NOTE: This only works because all the allowed hypercalls' input
> >  	 * structs begin with a u64 partition_id field.
> >  	 */
> > -	*(u64 *)input_pg = partition->pt_id;
> > +	*(u64 *)input_pg = pt_id;
> >  
> >  	if (args.reps)
> >  		status = hv_do_rep_hypercall(args.code, args.reps, 0,
> > @@ -226,7 +228,7 @@ static int mshv_ioctl_passthru_hvcall(struct mshv_partition *partition,
> >  	}
> >  
> >  	if (hv_result(status) == HV_STATUS_INSUFFICIENT_MEMORY) {
> > -		ret = hv_call_deposit_pages(NUMA_NO_NODE, partition->pt_id, 1);
> > +		ret = hv_call_deposit_pages(NUMA_NO_NODE, pt_id, 1);
> >  		if (!ret)
> >  			ret = -EAGAIN;
> >  	} else if (!hv_result_success(status)) {
> > @@ -2048,6 +2050,9 @@ static long mshv_dev_ioctl(struct file *filp, unsigned int ioctl,
> >  	case MSHV_CREATE_PARTITION:
> >  		return mshv_ioctl_create_partition((void __user *)arg,
> >  						misc->this_device);
> > +	case MSHV_ROOT_HVCALL:
> > +		return mshv_ioctl_passthru_hvcall(NULL, false,
> > +					(void __user *)arg);
> >  	}
> >  
> >  	return -ENOTTY;
> > -- 
> > 2.34.1
> > 

Re: [PATCH] Drivers: hv: ioctl for self targeted passthrough hvcalls

[Wei Liu]

On Sat, Nov 15, 2025 at 01:09:12PM +0530, Anirudh Rayabharam wrote:
> On Sat, Nov 15, 2025 at 06:22:40AM +0000, Wei Liu wrote:
> > On Fri, Nov 14, 2025 at 09:58:52AM +0000, Anirudh Rayabharam wrote:
> > > From: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com>
> > > 
> > > Allow MSHV_ROOT_HVCALL IOCTL on the /dev/mshv fd. This IOCTL would
> > > execute a passthrough hypercall targeting the root/parent partition
> > > i.e. HV_PARTITION_ID_SELF.
> > > 
> > > This will be useful for the VMM to query things like supported
> > > synthetic processor features, supported VMM capabiliites etc.
> > > 
> > > While at it, add HVCALL_GET_PARTITION_PROPERTY_EX to the allowed list of
> > > passthrough hypercalls.
> > > 
> > > Signed-off-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com>
> > 
> > This doesn't apply to hyperv-next. What's its base?
> 
> Hmmm... I remember doing this on hyperv-next. This the parent I see:
> 
> commit f2329fd987a0da4759c307c46fd27c4d05bb7433
> Author: Naman Jain <namjain@linux.microsoft.com>
> Date:   Thu Nov 13 04:41:49 2025 +0000
> 
>     Drivers: hv: Introduce mshv_vtl driver
> 
> No worries, I can rebase it on hyperv-next and send it again.

I pulled in some patches from hyperv-fixes to hyperv-next. That's
probably why. But you will see that eventually during a merge later
anyway, so it is good to just rebase and resend.

Wei

> 
> Thanks,
> Anirudh.
> 

Re: [PATCH] Drivers: hv: ioctl for self targeted passthrough hvcalls

[kernel test robot]

Hi Anirudh,

kernel test robot noticed the following build errors:

[auto build test ERROR on linus/master]
[also build test ERROR on v6.18-rc5]
[cannot apply to next-20251114]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Anirudh-Rayabharam/Drivers-hv-ioctl-for-self-targeted-passthrough-hvcalls/20251114-182039
base:   linus/master
patch link:    https://lore.kernel.org/r/20251114095853.3482596-1-anirudh%40anirudhrb.com
patch subject: [PATCH] Drivers: hv: ioctl for self targeted passthrough hvcalls
config: x86_64-buildonly-randconfig-005-20251116 (https://download.01.org/0day-ci/archive/20251116/202511161617.KcDzR4sA-lkp@intel.com/config)
compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251116/202511161617.KcDzR4sA-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202511161617.KcDzR4sA-lkp@intel.com/

All errors (new ones prefixed by >>):

>> drivers/hv/mshv_root_main.c:125:2: error: use of undeclared identifier 'HVCALL_GET_PARTITION_PROPERTY_EX'
     125 |         HVCALL_GET_PARTITION_PROPERTY_EX,
         |         ^
>> drivers/hv/mshv_root_main.c:175:18: error: invalid application of 'sizeof' to an incomplete type 'u16[]' (aka 'unsigned short[]')
     175 |         for (i = 0; i < ARRAY_SIZE(mshv_passthru_hvcalls); ++i)
         |                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/array_size.h:11:32: note: expanded from macro 'ARRAY_SIZE'
      11 | #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
         |                                ^~~~~
   drivers/hv/mshv_root_main.c:179:11: error: invalid application of 'sizeof' to an incomplete type 'u16[]' (aka 'unsigned short[]')
     179 |         if (i >= ARRAY_SIZE(mshv_passthru_hvcalls))
         |         ~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/array_size.h:11:32: note: expanded from macro 'ARRAY_SIZE'
      11 | #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
         |                                ^
   include/linux/compiler.h:55:47: note: expanded from macro 'if'
      55 | #define if(cond, ...) if ( __trace_if_var( !!(cond , ## __VA_ARGS__) ) )
         |                            ~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/compiler.h:57:52: note: expanded from macro '__trace_if_var'
      57 | #define __trace_if_var(cond) (__builtin_constant_p(cond) ? (cond) : __trace_if_value(cond))
         |                                                    ^~~~
   drivers/hv/mshv_root_main.c:179:11: error: invalid application of 'sizeof' to an incomplete type 'u16[]' (aka 'unsigned short[]')
     179 |         if (i >= ARRAY_SIZE(mshv_passthru_hvcalls))
         |         ~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/array_size.h:11:32: note: expanded from macro 'ARRAY_SIZE'
      11 | #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
         |                                ^
   include/linux/compiler.h:55:47: note: expanded from macro 'if'
      55 | #define if(cond, ...) if ( __trace_if_var( !!(cond , ## __VA_ARGS__) ) )
         |                            ~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/compiler.h:57:61: note: expanded from macro '__trace_if_var'
      57 | #define __trace_if_var(cond) (__builtin_constant_p(cond) ? (cond) : __trace_if_value(cond))
         |                                                             ^~~~
   drivers/hv/mshv_root_main.c:179:11: error: invalid application of 'sizeof' to an incomplete type 'u16[]' (aka 'unsigned short[]')
     179 |         if (i >= ARRAY_SIZE(mshv_passthru_hvcalls))
         |         ~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/array_size.h:11:32: note: expanded from macro 'ARRAY_SIZE'
      11 | #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
         |                                ^
   include/linux/compiler.h:55:47: note: expanded from macro 'if'
      55 | #define if(cond, ...) if ( __trace_if_var( !!(cond , ## __VA_ARGS__) ) )
         |                            ~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/compiler.h:57:86: note: expanded from macro '__trace_if_var'
      57 | #define __trace_if_var(cond) (__builtin_constant_p(cond) ? (cond) : __trace_if_value(cond))
         |                                                                     ~~~~~~~~~~~~~~~~~^~~~~
   include/linux/compiler.h:68:3: note: expanded from macro '__trace_if_value'
      68 |         (cond) ?                                        \
         |          ^~~~
   5 errors generated.


vim +/HVCALL_GET_PARTITION_PROPERTY_EX +125 drivers/hv/mshv_root_main.c

   117	
   118	/*
   119	 * Only allow hypercalls that have a u64 partition id as the first member of
   120	 * the input structure.
   121	 * These are sorted by value.
   122	 */
   123	static u16 mshv_passthru_hvcalls[] = {
   124		HVCALL_GET_PARTITION_PROPERTY,
 > 125		HVCALL_GET_PARTITION_PROPERTY_EX,
   126		HVCALL_SET_PARTITION_PROPERTY,
   127		HVCALL_INSTALL_INTERCEPT,
   128		HVCALL_GET_VP_REGISTERS,
   129		HVCALL_SET_VP_REGISTERS,
   130		HVCALL_TRANSLATE_VIRTUAL_ADDRESS,
   131		HVCALL_CLEAR_VIRTUAL_INTERRUPT,
   132		HVCALL_REGISTER_INTERCEPT_RESULT,
   133		HVCALL_ASSERT_VIRTUAL_INTERRUPT,
   134		HVCALL_GET_GPA_PAGES_ACCESS_STATES,
   135		HVCALL_SIGNAL_EVENT_DIRECT,
   136		HVCALL_POST_MESSAGE_DIRECT,
   137		HVCALL_GET_VP_CPUID_VALUES,
   138	};
   139	
   140	static bool mshv_hvcall_is_async(u16 code)
   141	{
   142		switch (code) {
   143		case HVCALL_SET_PARTITION_PROPERTY:
   144			return true;
   145		default:
   146			break;
   147		}
   148		return false;
   149	}
   150	
   151	static int mshv_ioctl_passthru_hvcall(struct mshv_partition *partition,
   152					      bool partition_locked,
   153					      void __user *user_args)
   154	{
   155		u64 status;
   156		int ret = 0, i;
   157		bool is_async;
   158		struct mshv_root_hvcall args;
   159		struct page *page;
   160		unsigned int pages_order;
   161		void *input_pg = NULL;
   162		void *output_pg = NULL;
   163		u64 pt_id = partition ? partition->pt_id : HV_PARTITION_ID_SELF;
   164	
   165		if (copy_from_user(&args, user_args, sizeof(args)))
   166			return -EFAULT;
   167	
   168		if (args.status || !args.in_ptr || args.in_sz < sizeof(u64) ||
   169		    mshv_field_nonzero(args, rsvd) || args.in_sz > HV_HYP_PAGE_SIZE)
   170			return -EINVAL;
   171	
   172		if (args.out_ptr && (!args.out_sz || args.out_sz > HV_HYP_PAGE_SIZE))
   173			return -EINVAL;
   174	
 > 175		for (i = 0; i < ARRAY_SIZE(mshv_passthru_hvcalls); ++i)
   176			if (args.code == mshv_passthru_hvcalls[i])
   177				break;
   178	
   179		if (i >= ARRAY_SIZE(mshv_passthru_hvcalls))
   180			return -EINVAL;
   181	
   182		is_async = mshv_hvcall_is_async(args.code);
   183		if (is_async) {
   184			/* async hypercalls can only be called from partition fd */
   185			if (!partition || !partition_locked)
   186				return -EINVAL;
   187			ret = mshv_init_async_handler(partition);
   188			if (ret)
   189				return ret;
   190		}
   191	
   192		pages_order = args.out_ptr ? 1 : 0;
   193		page = alloc_pages(GFP_KERNEL, pages_order);
   194		if (!page)
   195			return -ENOMEM;
   196		input_pg = page_address(page);
   197	
   198		if (args.out_ptr)
   199			output_pg = (char *)input_pg + PAGE_SIZE;
   200		else
   201			output_pg = NULL;
   202	
   203		if (copy_from_user(input_pg, (void __user *)args.in_ptr,
   204				   args.in_sz)) {
   205			ret = -EFAULT;
   206			goto free_pages_out;
   207		}
   208	
   209		/*
   210		 * NOTE: This only works because all the allowed hypercalls' input
   211		 * structs begin with a u64 partition_id field.
   212		 */
   213		*(u64 *)input_pg = pt_id;
   214	
   215		if (args.reps)
   216			status = hv_do_rep_hypercall(args.code, args.reps, 0,
   217						     input_pg, output_pg);
   218		else
   219			status = hv_do_hypercall(args.code, input_pg, output_pg);
   220	
   221		if (hv_result(status) == HV_STATUS_CALL_PENDING) {
   222			if (is_async) {
   223				mshv_async_hvcall_handler(partition, &status);
   224			} else { /* Paranoia check. This shouldn't happen! */
   225				ret = -EBADFD;
   226				goto free_pages_out;
   227			}
   228		}
   229	
   230		if (hv_result(status) == HV_STATUS_INSUFFICIENT_MEMORY) {
   231			ret = hv_call_deposit_pages(NUMA_NO_NODE, pt_id, 1);
   232			if (!ret)
   233				ret = -EAGAIN;
   234		} else if (!hv_result_success(status)) {
   235			ret = hv_result_to_errno(status);
   236		}
   237	
   238		/*
   239		 * Always return the status and output data regardless of result.
   240		 * The VMM may need it to determine how to proceed. E.g. the status may
   241		 * contain the number of reps completed if a rep hypercall partially
   242		 * succeeded.
   243		 */
   244		args.status = hv_result(status);
   245		args.reps = args.reps ? hv_repcomp(status) : 0;
   246		if (copy_to_user(user_args, &args, sizeof(args)))
   247			ret = -EFAULT;
   248	
   249		if (output_pg &&
   250		    copy_to_user((void __user *)args.out_ptr, output_pg, args.out_sz))
   251			ret = -EFAULT;
   252	
   253	free_pages_out:
   254		free_pages((unsigned long)input_pg, pages_order);
   255	
   256		return ret;
   257	}
   258	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [PATCH] Drivers: hv: ioctl for self targeted passthrough hvcalls

[Wei Liu]

+Nuno

On Sun, Nov 16, 2025 at 04:17:08PM +0800, kernel test robot wrote:
> Hi Anirudh,
> 
> kernel test robot noticed the following build errors:
> 
> [auto build test ERROR on linus/master]
> [also build test ERROR on v6.18-rc5]
> [cannot apply to next-20251114]
> [If your patch is applied to the wrong git tree, kindly drop us a note.
> And when submitting patch, we suggest to use '--base' as documented in
> https://git-scm.com/docs/git-format-patch#_base_tree_information]
> 
> url:    https://github.com/intel-lab-lkp/linux/commits/Anirudh-Rayabharam/Drivers-hv-ioctl-for-self-targeted-passthrough-hvcalls/20251114-182039
> base:   linus/master
> patch link:    https://lore.kernel.org/r/20251114095853.3482596-1-anirudh%40anirudhrb.com
> patch subject: [PATCH] Drivers: hv: ioctl for self targeted passthrough hvcalls
> config: x86_64-buildonly-randconfig-005-20251116 (https://download.01.org/0day-ci/archive/20251116/202511161617.KcDzR4sA-lkp@intel.com/config)
> compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251116/202511161617.KcDzR4sA-lkp@intel.com/reproduce)
> 
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@intel.com>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202511161617.KcDzR4sA-lkp@intel.com/
> 
> All errors (new ones prefixed by >>):
> 
> >> drivers/hv/mshv_root_main.c:125:2: error: use of undeclared identifier 'HVCALL_GET_PARTITION_PROPERTY_EX'
>      125 |         HVCALL_GET_PARTITION_PROPERTY_EX,
>          |         ^

Anirudh, please check this.

> >> drivers/hv/mshv_root_main.c:175:18: error: invalid application of 'sizeof' to an incomplete type 'u16[]' (aka 'unsigned short[]')
>      175 |         for (i = 0; i < ARRAY_SIZE(mshv_passthru_hvcalls); ++i)
>          |                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

This is from the original patch. Perhaps adding the explicit declaration
of the array size would help.

Wei

Re: [PATCH] Drivers: hv: ioctl for self targeted passthrough hvcalls

[Nuno Das Neves]

On 11/17/2025 9:34 AM, Wei Liu wrote:
> +Nuno
> 
> On Sun, Nov 16, 2025 at 04:17:08PM +0800, kernel test robot wrote:
>> Hi Anirudh,
>>
>> kernel test robot noticed the following build errors:
>>
>> [auto build test ERROR on linus/master]
>> [also build test ERROR on v6.18-rc5]
>> [cannot apply to next-20251114]
>> [If your patch is applied to the wrong git tree, kindly drop us a note.
>> And when submitting patch, we suggest to use '--base' as documented in
>> https://git-scm.com/docs/git-format-patch#_base_tree_information]
>>
>> url:    https://github.com/intel-lab-lkp/linux/commits/Anirudh-Rayabharam/Drivers-hv-ioctl-for-self-targeted-passthrough-hvcalls/20251114-182039
>> base:   linus/master
>> patch link:    https://lore.kernel.org/r/20251114095853.3482596-1-anirudh%40anirudhrb.com
>> patch subject: [PATCH] Drivers: hv: ioctl for self targeted passthrough hvcalls
>> config: x86_64-buildonly-randconfig-005-20251116 (https://download.01.org/0day-ci/archive/20251116/202511161617.KcDzR4sA-lkp@intel.com/config)
>> compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
>> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251116/202511161617.KcDzR4sA-lkp@intel.com/reproduce)
>>
>> If you fix the issue in a separate patch/commit (i.e. not just a new version of
>> the same patch/commit), kindly add following tags
>> | Reported-by: kernel test robot <lkp@intel.com>
>> | Closes: https://lore.kernel.org/oe-kbuild-all/202511161617.KcDzR4sA-lkp@intel.com/
>>
>> All errors (new ones prefixed by >>):
>>
>>>> drivers/hv/mshv_root_main.c:125:2: error: use of undeclared identifier 'HVCALL_GET_PARTITION_PROPERTY_EX'
>>      125 |         HVCALL_GET_PARTITION_PROPERTY_EX,
>>          |         ^
> 
> Anirudh, please check this.
> 
This is introduced in hyperv-next, in:
59aeea195948 mshv: Add the HVCALL_GET_PARTITION_PROPERTY_EX hypercall

But the bot applies the patch to linus/master, that is probably why.

>>>> drivers/hv/mshv_root_main.c:175:18: error: invalid application of 'sizeof' to an incomplete type 'u16[]' (aka 'unsigned short[]')
>>      175 |         for (i = 0; i < ARRAY_SIZE(mshv_passthru_hvcalls); ++i)
>>          |                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 
> This is from the original patch. Perhaps adding the explicit declaration
> of the array size would help.
> 

I think this is just due to the earlier error...

Nuno

> Wei

Re: [PATCH] Drivers: hv: ioctl for self targeted passthrough hvcalls

[Anirudh Rayabharam]

On Mon, Nov 17, 2025 at 09:41:19AM -0800, Nuno Das Neves wrote:
> On 11/17/2025 9:34 AM, Wei Liu wrote:
> > +Nuno
> > 
> > On Sun, Nov 16, 2025 at 04:17:08PM +0800, kernel test robot wrote:
> >> Hi Anirudh,
> >>
> >> kernel test robot noticed the following build errors:
> >>
> >> [auto build test ERROR on linus/master]
> >> [also build test ERROR on v6.18-rc5]
> >> [cannot apply to next-20251114]
> >> [If your patch is applied to the wrong git tree, kindly drop us a note.
> >> And when submitting patch, we suggest to use '--base' as documented in
> >> https://git-scm.com/docs/git-format-patch#_base_tree_information]
> >>
> >> url:    https://github.com/intel-lab-lkp/linux/commits/Anirudh-Rayabharam/Drivers-hv-ioctl-for-self-targeted-passthrough-hvcalls/20251114-182039
> >> base:   linus/master
> >> patch link:    https://lore.kernel.org/r/20251114095853.3482596-1-anirudh%40anirudhrb.com
> >> patch subject: [PATCH] Drivers: hv: ioctl for self targeted passthrough hvcalls
> >> config: x86_64-buildonly-randconfig-005-20251116 (https://download.01.org/0day-ci/archive/20251116/202511161617.KcDzR4sA-lkp@intel.com/config)
> >> compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
> >> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251116/202511161617.KcDzR4sA-lkp@intel.com/reproduce)
> >>
> >> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> >> the same patch/commit), kindly add following tags
> >> | Reported-by: kernel test robot <lkp@intel.com>
> >> | Closes: https://lore.kernel.org/oe-kbuild-all/202511161617.KcDzR4sA-lkp@intel.com/
> >>
> >> All errors (new ones prefixed by >>):
> >>
> >>>> drivers/hv/mshv_root_main.c:125:2: error: use of undeclared identifier 'HVCALL_GET_PARTITION_PROPERTY_EX'
> >>      125 |         HVCALL_GET_PARTITION_PROPERTY_EX,
> >>          |         ^
> > 
> > Anirudh, please check this.
> > 
> This is introduced in hyperv-next, in:
> 59aeea195948 mshv: Add the HVCALL_GET_PARTITION_PROPERTY_EX hypercall
> 
> But the bot applies the patch to linus/master, that is probably why.

Right. In the v2 of this patch, I used the --base argument to git
format-patch as suggested by the tool above. That should help it apply
the patch in the right tree. Let's see if it still complains.

Anirudh

> 
> >>>> drivers/hv/mshv_root_main.c:175:18: error: invalid application of 'sizeof' to an incomplete type 'u16[]' (aka 'unsigned short[]')
> >>      175 |         for (i = 0; i < ARRAY_SIZE(mshv_passthru_hvcalls); ++i)
> >>          |                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > 
> > This is from the original patch. Perhaps adding the explicit declaration
> > of the array size would help.
> > 
> 
> I think this is just due to the earlier error...
> 
> Nuno
> 
> > Wei
>