On 5/4/2026 9:36 PM, Michael Kelley wrote:
From: Naman Jain <[email protected]> Sent: Wednesday, April 29, 2026
2:57 AM
On 4/27/2026 11:08 AM, Michael Kelley wrote:
From: Naman Jain <[email protected]> Sent: Thursday, April 23, 2026
5:42 AM
[snip]
diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index 08278547b84c..b4d80c9a673a 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -286,7 +286,6 @@ struct mshv_vtl_cpu_context {
#ifdef CONFIG_HYPERV_VTL_MODE
void __init hv_vtl_init_platform(void);
int __init hv_vtl_early_init(void);
-void mshv_vtl_return_call(struct mshv_vtl_cpu_context *vtl0);
void mshv_vtl_return_call_init(u64 vtl_return_offset);
void mshv_vtl_return_hypercall(void);
void __mshv_vtl_return_call(struct mshv_vtl_cpu_context *vtl0);
@@ -294,7 +293,6 @@ int hv_vtl_get_set_reg(struct hv_register_assoc *regs, bool
set, bool shared);
#else
static inline void __init hv_vtl_init_platform(void) {}
static inline int __init hv_vtl_early_init(void) { return 0; }
-static inline void mshv_vtl_return_call(struct mshv_vtl_cpu_context *vtl0) {}
static inline void mshv_vtl_return_call_init(u64 vtl_return_offset) {}
static inline void mshv_vtl_return_hypercall(void) {}
static inline void __mshv_vtl_return_call(struct mshv_vtl_cpu_context *vtl0)
{}
diff --git a/drivers/hv/mshv_vtl.h b/drivers/hv/mshv_vtl.h
index a6eea52f7aa2..103f07371f3f 100644
--- a/drivers/hv/mshv_vtl.h
+++ b/drivers/hv/mshv_vtl.h
@@ -22,4 +22,7 @@ struct mshv_vtl_run {
char vtl_ret_actions[MSHV_MAX_RUN_MSG_SIZE];
};
+static_assert(sizeof(struct mshv_vtl_cpu_context) <= 1024,
+ "struct mshv_vtl_cpu_context exceeds reserved space in struct
mshv_vtl_run");
+
#endif /* _MSHV_VTL_H */
diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
index db183c8cfb95..8cdf2a9fbdfb 100644
--- a/include/asm-generic/mshyperv.h
+++ b/include/asm-generic/mshyperv.h
@@ -396,8 +396,10 @@ static inline int hv_deposit_memory(u64 partition_id, u64
status)
#if IS_ENABLED(CONFIG_HYPERV_VTL_MODE)
u8 __init get_vtl(void);
+void mshv_vtl_return_call(struct mshv_vtl_cpu_context *vtl0);
#else
static inline u8 get_vtl(void) { return 0; }
+static inline void mshv_vtl_return_call(struct mshv_vtl_cpu_context *vtl0) {}
Is this stub needed? Maybe I missed something, but it looks to me like none
of the code that calls this gets built unless CONFIG_HYPERV_VTL_MODE is set.
See further comments about stubs in Patch 8 of this series.
Config dependencies would handle such cases, and this is not required. I
saw similar stubs added in the code, so I thought this is a norm that
should be followed, and not rely on config dependencies.
I can remove it.
Others might disagree with me, but I don't think it's the norm to add
stubs when they aren't truly needed. As you can see from some of my
other comments, I look for ways to eliminate stubs. Stubs are indicative
of a boundary between separately built components, and I generally
try to minimize the surface area of such boundaries. A large surface area
often means that the overall design could be improved by re-thinking
which code goes with which component.
Michael
I agree. I'll remove these in next version.
Thanks,
Naman
