Commit 9263abc7 authored by Roman Kisel's avatar Roman Kisel Committed by Wei Liu
Browse files

hyperv: Enable the hypercall output page for the VTL mode 



Due to the hypercall page not being allocated in the VTL mode,
the code resorts to using a part of the input page.

Allocate the hypercall output page in the VTL mode thus enabling
it to use it for output and share code with dom0.

Signed-off-by: default avatarRoman Kisel <romank@linux.microsoft.com>
Reviewed-by: default avatarNuno Das Neves <nunodasneves@linux.microsoft.com>
Link: https://lore.kernel.org/r/20250108222138.1623703-4-romank@linux.microsoft.com


Signed-off-by: default avatarWei Liu <wei.liu@kernel.org>
Message-ID: <20250108222138.1623703-4-romank@linux.microsoft.com>
parent 1da602ec

drivers/hv/hv_common.c

+8 −3
Original line number Diff line number Diff line
@@ -278,6 +278,11 @@ static void hv_kmsg_dump_register(void) 
	}

}



static inline bool hv_output_page_exists(void)

{

	return hv_root_partition || IS_ENABLED(CONFIG_HYPERV_VTL_MODE);

}



int __init hv_common_init(void)

{

	int i;
@@ -340,7 +345,7 @@ int __init hv_common_init(void) 
	BUG_ON(!hyperv_pcpu_input_arg);



	/* Allocate the per-CPU state for output arg for root */

	if (hv_root_partition) {

	if (hv_output_page_exists()) {

		hyperv_pcpu_output_arg = alloc_percpu(void *);

		BUG_ON(!hyperv_pcpu_output_arg);

	}
@@ -435,7 +440,7 @@ int hv_common_cpu_init(unsigned int cpu) 
	void **inputarg, **outputarg;

	u64 msr_vp_index;

	gfp_t flags;

	int pgcount = hv_root_partition ? 2 : 1;

	const int pgcount = hv_output_page_exists() ? 2 : 1;

	void *mem;

	int ret;
@@ -453,7 +458,7 @@ int hv_common_cpu_init(unsigned int cpu) 
		if (!mem)

			return -ENOMEM;



		if (hv_root_partition) {

		if (hv_output_page_exists()) {

			outputarg = (void **)this_cpu_ptr(hyperv_pcpu_output_arg);

			*outputarg = (char *)mem + HV_HYP_PAGE_SIZE;

		}