From: Naman Jain <namjain@linux.microsoft.com>
To: "K . Y . Srinivasan" <kys@microsoft.com>,
Haiyang Zhang <haiyangz@microsoft.com>,
Wei Liu <wei.liu@kernel.org>, Dexuan Cui <decui@microsoft.com>,
Long Li <longli@microsoft.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>, Thomas Gleixner <tglx@kernel.org>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
x86@kernel.org, "H . Peter Anvin" <hpa@zytor.com>,
Arnd Bergmann <arnd@arndb.de>, Paul Walmsley <pjw@kernel.org>,
Palmer Dabbelt <palmer@dabbelt.com>,
Albert Ou <aou@eecs.berkeley.edu>,
Alexandre Ghiti <alex@ghiti.fr>
Cc: Marc Zyngier <maz@kernel.org>,
Timothy Hayes <timothy.hayes@arm.com>,
Lorenzo Pieralisi <lpieralisi@kernel.org>,
mrigendrachaubey <mrigendra.chaubey@gmail.com>,
Naman Jain <namjain@linux.microsoft.com>,
ssengar@linux.microsoft.com,
Michael Kelley <mhklinux@outlook.com>,
linux-hyperv@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org,
linux-riscv@lists.infradead.org
Subject: [PATCH 08/11] Drivers: hv: mshv_vtl: Move register page config to arch-specific files
Date: Mon, 16 Mar 2026 12:12:38 +0000 [thread overview]
Message-ID: <20260316121241.910764-9-namjain@linux.microsoft.com> (raw)
In-Reply-To: <20260316121241.910764-1-namjain@linux.microsoft.com>
Move mshv_vtl_configure_reg_page() implementation from
drivers/hv/mshv_vtl_main.c to arch-specific files:
- arch/x86/hyperv/hv_vtl.c: full implementation with register page setup
- arch/arm64/hyperv/hv_vtl.c: stub implementation (unsupported)
Move common type definitions to include/asm-generic/mshyperv.h:
- struct mshv_vtl_per_cpu
- union hv_synic_overlay_page_msr
Move hv_call_get_vp_registers() and hv_call_set_vp_registers()
declarations to include/asm-generic/mshyperv.h since these functions
are used by multiple modules.
While at it, remove the unnecessary stub implementations in #else
case for mshv_vtl_return* functions in arch/x86/include/asm/mshyperv.h.
This is essential for adding support for ARM64 in MSHV_VTL.
Signed-off-by: Naman Jain <namjain@linux.microsoft.com>
---
arch/arm64/hyperv/hv_vtl.c | 8 +++++
arch/arm64/include/asm/mshyperv.h | 3 ++
arch/x86/hyperv/hv_vtl.c | 32 ++++++++++++++++++++
arch/x86/include/asm/mshyperv.h | 7 ++---
drivers/hv/mshv.h | 8 -----
drivers/hv/mshv_vtl_main.c | 49 +++----------------------------
include/asm-generic/mshyperv.h | 42 ++++++++++++++++++++++++++
7 files changed, 92 insertions(+), 57 deletions(-)
diff --git a/arch/arm64/hyperv/hv_vtl.c b/arch/arm64/hyperv/hv_vtl.c
index 66318672c242..d699138427c1 100644
--- a/arch/arm64/hyperv/hv_vtl.c
+++ b/arch/arm64/hyperv/hv_vtl.c
@@ -10,6 +10,7 @@
#include <asm/boot.h>
#include <asm/mshyperv.h>
#include <asm/cpu_ops.h>
+#include <linux/export.h>
void mshv_vtl_return_call(struct mshv_vtl_cpu_context *vtl0)
{
@@ -142,3 +143,10 @@ void mshv_vtl_return_call(struct mshv_vtl_cpu_context *vtl0)
"v24", "v25", "v26", "v27", "v28", "v29", "v30", "v31");
}
EXPORT_SYMBOL(mshv_vtl_return_call);
+
+bool hv_vtl_configure_reg_page(struct mshv_vtl_per_cpu *per_cpu)
+{
+ pr_debug("Register page not supported on ARM64\n");
+ return false;
+}
+EXPORT_SYMBOL_GPL(hv_vtl_configure_reg_page);
diff --git a/arch/arm64/include/asm/mshyperv.h b/arch/arm64/include/asm/mshyperv.h
index de7f3a41a8ea..36803f0386cc 100644
--- a/arch/arm64/include/asm/mshyperv.h
+++ b/arch/arm64/include/asm/mshyperv.h
@@ -61,6 +61,8 @@ static inline u64 hv_get_non_nested_msr(unsigned int reg)
ARM_SMCCC_OWNER_VENDOR_HYP, \
HV_SMCCC_FUNC_NUMBER)
+struct mshv_vtl_per_cpu;
+
struct mshv_vtl_cpu_context {
/*
* NOTE: x18 is managed by the hypervisor. It won't be reloaded from this array.
@@ -82,6 +84,7 @@ static inline int hv_vtl_get_set_reg(struct hv_register_assoc *regs, bool set, u
}
void mshv_vtl_return_call(struct mshv_vtl_cpu_context *vtl0);
+bool hv_vtl_configure_reg_page(struct mshv_vtl_per_cpu *per_cpu);
#endif
#include <asm-generic/mshyperv.h>
diff --git a/arch/x86/hyperv/hv_vtl.c b/arch/x86/hyperv/hv_vtl.c
index 72a0bb4ae0c7..ede290985d41 100644
--- a/arch/x86/hyperv/hv_vtl.c
+++ b/arch/x86/hyperv/hv_vtl.c
@@ -20,6 +20,7 @@
#include <uapi/asm/mtrr.h>
#include <asm/debugreg.h>
#include <linux/export.h>
+#include <linux/hyperv.h>
#include <../kernel/smpboot.h>
#include "../../kernel/fpu/legacy.h"
@@ -259,6 +260,37 @@ int __init hv_vtl_early_init(void)
return 0;
}
+static const union hv_input_vtl input_vtl_zero;
+
+bool hv_vtl_configure_reg_page(struct mshv_vtl_per_cpu *per_cpu)
+{
+ struct hv_register_assoc reg_assoc = {};
+ union hv_synic_overlay_page_msr overlay = {};
+ struct page *reg_page;
+
+ reg_page = alloc_page(GFP_KERNEL | __GFP_ZERO | __GFP_RETRY_MAYFAIL);
+ if (!reg_page) {
+ WARN(1, "failed to allocate register page\n");
+ return false;
+ }
+
+ overlay.enabled = 1;
+ overlay.pfn = page_to_hvpfn(reg_page);
+ reg_assoc.name = HV_X64_REGISTER_REG_PAGE;
+ reg_assoc.value.reg64 = overlay.as_uint64;
+
+ if (hv_call_set_vp_registers(HV_VP_INDEX_SELF, HV_PARTITION_ID_SELF,
+ 1, input_vtl_zero, ®_assoc)) {
+ WARN(1, "failed to setup register page\n");
+ __free_page(reg_page);
+ return false;
+ }
+
+ per_cpu->reg_page = reg_page;
+ return true;
+}
+EXPORT_SYMBOL_GPL(hv_vtl_configure_reg_page);
+
DEFINE_STATIC_CALL_NULL(__mshv_vtl_return_hypercall, void (*)(void));
void mshv_vtl_return_call_init(u64 vtl_return_offset)
diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index d5355a5b7517..d592fea49cdb 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -271,6 +271,8 @@ static inline u64 hv_get_non_nested_msr(unsigned int reg) { return 0; }
static inline int hv_apicid_to_vp_index(u32 apic_id) { return -EINVAL; }
#endif /* CONFIG_HYPERV */
+struct mshv_vtl_per_cpu;
+
struct mshv_vtl_cpu_context {
union {
struct {
@@ -305,13 +307,10 @@ 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);
int hv_vtl_get_set_reg(struct hv_register_assoc *regs, bool set, u64 shared);
+bool hv_vtl_configure_reg_page(struct mshv_vtl_per_cpu *per_cpu);
#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) {}
#endif
#include <asm-generic/mshyperv.h>
diff --git a/drivers/hv/mshv.h b/drivers/hv/mshv.h
index d4813df92b9c..0fcb7f9ba6a9 100644
--- a/drivers/hv/mshv.h
+++ b/drivers/hv/mshv.h
@@ -14,14 +14,6 @@
memchr_inv(&((STRUCT).MEMBER), \
0, sizeof_field(typeof(STRUCT), MEMBER))
-int hv_call_get_vp_registers(u32 vp_index, u64 partition_id, u16 count,
- union hv_input_vtl input_vtl,
- struct hv_register_assoc *registers);
-
-int hv_call_set_vp_registers(u32 vp_index, u64 partition_id, u16 count,
- union hv_input_vtl input_vtl,
- struct hv_register_assoc *registers);
-
int hv_call_get_partition_property(u64 partition_id, u64 property_code,
u64 *property_value);
diff --git a/drivers/hv/mshv_vtl_main.c b/drivers/hv/mshv_vtl_main.c
index 91517b45d526..c79d24317b8e 100644
--- a/drivers/hv/mshv_vtl_main.c
+++ b/drivers/hv/mshv_vtl_main.c
@@ -78,21 +78,6 @@ struct mshv_vtl {
u64 id;
};
-struct mshv_vtl_per_cpu {
- struct mshv_vtl_run *run;
- struct page *reg_page;
-};
-
-/* SYNIC_OVERLAY_PAGE_MSR - internal, identical to hv_synic_simp */
-union hv_synic_overlay_page_msr {
- u64 as_uint64;
- struct {
- u64 enabled: 1;
- u64 reserved: 11;
- u64 pfn: 52;
- } __packed;
-};
-
static struct mutex mshv_vtl_poll_file_lock;
static union hv_register_vsm_page_offsets mshv_vsm_page_offsets;
static union hv_register_vsm_capabilities mshv_vsm_capabilities;
@@ -201,34 +186,6 @@ static struct page *mshv_vtl_cpu_reg_page(int cpu)
return *per_cpu_ptr(&mshv_vtl_per_cpu.reg_page, cpu);
}
-static void mshv_vtl_configure_reg_page(struct mshv_vtl_per_cpu *per_cpu)
-{
- struct hv_register_assoc reg_assoc = {};
- union hv_synic_overlay_page_msr overlay = {};
- struct page *reg_page;
-
- reg_page = alloc_page(GFP_KERNEL | __GFP_ZERO | __GFP_RETRY_MAYFAIL);
- if (!reg_page) {
- WARN(1, "failed to allocate register page\n");
- return;
- }
-
- overlay.enabled = 1;
- overlay.pfn = page_to_hvpfn(reg_page);
- reg_assoc.name = HV_X64_REGISTER_REG_PAGE;
- reg_assoc.value.reg64 = overlay.as_uint64;
-
- if (hv_call_set_vp_registers(HV_VP_INDEX_SELF, HV_PARTITION_ID_SELF,
- 1, input_vtl_zero, ®_assoc)) {
- WARN(1, "failed to setup register page\n");
- __free_page(reg_page);
- return;
- }
-
- per_cpu->reg_page = reg_page;
- mshv_has_reg_page = true;
-}
-
static void mshv_vtl_synic_enable_regs(unsigned int cpu)
{
union hv_synic_sint sint;
@@ -329,8 +286,10 @@ static int mshv_vtl_alloc_context(unsigned int cpu)
if (!per_cpu->run)
return -ENOMEM;
- if (mshv_vsm_capabilities.intercept_page_available)
- mshv_vtl_configure_reg_page(per_cpu);
+ if (mshv_vsm_capabilities.intercept_page_available) {
+ if (hv_vtl_configure_reg_page(per_cpu))
+ mshv_has_reg_page = true;
+ }
mshv_vtl_synic_enable_regs(cpu);
diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
index b147a12085e4..b53fcc071596 100644
--- a/include/asm-generic/mshyperv.h
+++ b/include/asm-generic/mshyperv.h
@@ -383,8 +383,50 @@ static inline int hv_deposit_memory(u64 partition_id, u64 status)
return hv_deposit_memory_node(NUMA_NO_NODE, partition_id, status);
}
+#if IS_ENABLED(CONFIG_MSHV_ROOT) || IS_ENABLED(CONFIG_MSHV_VTL)
+int hv_call_get_vp_registers(u32 vp_index, u64 partition_id, u16 count,
+ union hv_input_vtl input_vtl,
+ struct hv_register_assoc *registers);
+
+int hv_call_set_vp_registers(u32 vp_index, u64 partition_id, u16 count,
+ union hv_input_vtl input_vtl,
+ struct hv_register_assoc *registers);
+#else
+static inline int hv_call_get_vp_registers(u32 vp_index, u64 partition_id,
+ u16 count,
+ union hv_input_vtl input_vtl,
+ struct hv_register_assoc *registers)
+{
+ return -EOPNOTSUPP;
+}
+
+static inline int hv_call_set_vp_registers(u32 vp_index, u64 partition_id,
+ u16 count,
+ union hv_input_vtl input_vtl,
+ struct hv_register_assoc *registers)
+{
+ return -EOPNOTSUPP;
+}
+#endif /* CONFIG_MSHV_ROOT || CONFIG_MSHV_VTL */
+
#define HV_VP_ASSIST_PAGE_ADDRESS_SHIFT 12
+
#if IS_ENABLED(CONFIG_HYPERV_VTL_MODE)
+struct mshv_vtl_per_cpu {
+ struct mshv_vtl_run *run;
+ struct page *reg_page;
+};
+
+/* SYNIC_OVERLAY_PAGE_MSR - internal, identical to hv_synic_simp */
+union hv_synic_overlay_page_msr {
+ u64 as_uint64;
+ struct {
+ u64 enabled: 1;
+ u64 reserved: 11;
+ u64 pfn: 52;
+ } __packed;
+};
+
u8 __init get_vtl(void);
#else
static inline u8 get_vtl(void) { return 0; }
--
2.43.0
next prev parent reply other threads:[~2026-03-16 12:14 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-16 12:12 [PATCH 00/11] Drivers: hv: Add ARM64 support in mshv_vtl Naman Jain
2026-03-16 12:12 ` [PATCH 01/11] arch: arm64: Export arch_smp_send_reschedule for mshv_vtl module Naman Jain
2026-03-16 12:12 ` [PATCH 02/11] Drivers: hv: Move hv_vp_assist_page to common files Naman Jain
2026-03-16 12:12 ` [PATCH 03/11] Drivers: hv: Add support to setup percpu vmbus handler Naman Jain
2026-03-16 12:12 ` [PATCH 04/11] Drivers: hv: Refactor mshv_vtl for ARM64 support to be added Naman Jain
2026-03-16 12:12 ` [PATCH 05/11] drivers: hv: Export vmbus_interrupt for mshv_vtl module Naman Jain
2026-03-16 12:12 ` [PATCH 06/11] Drivers: hv: Make sint vector architecture neutral in MSHV_VTL Naman Jain
2026-03-16 12:12 ` [PATCH 07/11] arch: arm64: Add support for mshv_vtl_return_call Naman Jain
2026-03-16 12:12 ` Naman Jain [this message]
2026-03-16 12:12 ` [PATCH 09/11] Drivers: hv: mshv_vtl: Let userspace do VSM configuration Naman Jain
2026-03-16 12:12 ` [PATCH 10/11] Drivers: hv: Add support for arm64 in MSHV_VTL Naman Jain
2026-03-16 12:12 ` [PATCH 11/11] Drivers: hv: Kconfig: Add ARM64 support for MSHV_VTL Naman Jain
2026-03-17 3:34 ` [PATCH 00/11] Drivers: hv: Add ARM64 support in mshv_vtl vdso
2026-03-17 9:51 ` Naman Jain
2026-03-17 22:03 ` Michael Kelley
2026-03-18 4:23 ` Naman Jain
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