[-next,v15,08/19] riscv: Introduce struct/helpers to save/restore per-task Vector state

Commit Message

Andy Chiu March 17, 2023, 11:35 a.m. UTC

From: Greentime Hu <[e-mail]>

Add vector state context struct to be added later in thread_struct. And
prepare low-level helper functions to save/restore vector contexts.

This include Vector Regfile and CSRs holding dynamic configuration state
(vstart, vl, vtype, vcsr). The Vec Register width could be implementation
defined, but same for all processes, so that is saved separately.

This is not yet wired into final thread_struct - will be done when
__switch_to actually starts doing this in later patches.

Given the variable (and potentially large) size of regfile, they are
saved in dynamically allocated memory, pointed to by datap pointer in
__riscv_v_ext_state.

Co-developed-by: Vincent Chen <[e-mail]>
Signed-off-by: Vincent Chen <[e-mail]>
Signed-off-by: Greentime Hu <[e-mail]>
Signed-off-by: Vineet Gupta <[e-mail]>
Signed-off-by: Andy Chiu <[e-mail]>
---
 arch/riscv/include/asm/vector.h      | 97 ++++++++++++++++++++++++++++
 arch/riscv/include/uapi/asm/ptrace.h | 17 +++++
 2 files changed, 114 insertions(+)

Comments

Conor Dooley March 20, 2023, 1:05 p.m. UTC | #1

On Fri, Mar 17, 2023 at 11:35:27AM +0000, Andy Chiu wrote:
> From: Greentime Hu <[e-mail]>
> 
> Add vector state context struct to be added later in thread_struct. And
> prepare low-level helper functions to save/restore vector contexts.
> 
> This include Vector Regfile and CSRs holding dynamic configuration state
> (vstart, vl, vtype, vcsr). The Vec Register width could be implementation
> defined, but same for all processes, so that is saved separately.
> 
> This is not yet wired into final thread_struct - will be done when
> __switch_to actually starts doing this in later patches.
> 
> Given the variable (and potentially large) size of regfile, they are
> saved in dynamically allocated memory, pointed to by datap pointer in
> __riscv_v_ext_state.
> 
> Co-developed-by: Vincent Chen <[e-mail]>
> Signed-off-by: Vincent Chen <[e-mail]>
> Signed-off-by: Greentime Hu <[e-mail]>
> Signed-off-by: Vineet Gupta <[e-mail]>
> Signed-off-by: Andy Chiu <[e-mail]>

I think you missed a:
Acked-by: Conor Dooley <[e-mail]>

Thanks,
Conor.

> ---
>  arch/riscv/include/asm/vector.h      | 97 ++++++++++++++++++++++++++++
>  arch/riscv/include/uapi/asm/ptrace.h | 17 +++++
>  2 files changed, 114 insertions(+)
> 
> diff --git a/arch/riscv/include/asm/vector.h b/arch/riscv/include/asm/vector.h
> index 18448e24d77b..c7143b7d64d1 100644
> --- a/arch/riscv/include/asm/vector.h
> +++ b/arch/riscv/include/asm/vector.h
> @@ -10,8 +10,10 @@
>  
>  #ifdef CONFIG_RISCV_ISA_V
>  
> +#include <linux/stringify.h>
>  #include <asm/hwcap.h>
>  #include <asm/csr.h>
> +#include <asm/asm.h>
>  
>  extern unsigned long riscv_v_vsize;
>  void riscv_v_setup_vsize(void);
> @@ -21,6 +23,26 @@ static __always_inline bool has_vector(void)
>  	return riscv_has_extension_likely(RISCV_ISA_EXT_v);
>  }
>  
> +static inline void __riscv_v_vstate_clean(struct pt_regs *regs)
> +{
> +	regs->status = (regs->status & ~SR_VS) | SR_VS_CLEAN;
> +}
> +
> +static inline void riscv_v_vstate_off(struct pt_regs *regs)
> +{
> +	regs->status = (regs->status & ~SR_VS) | SR_VS_OFF;
> +}
> +
> +static inline void riscv_v_vstate_on(struct pt_regs *regs)
> +{
> +	regs->status = (regs->status & ~SR_VS) | SR_VS_INITIAL;
> +}
> +
> +static inline bool riscv_v_vstate_query(struct pt_regs *regs)
> +{
> +	return (regs->status & SR_VS) != 0;
> +}
> +
>  static __always_inline void riscv_v_enable(void)
>  {
>  	csr_set(CSR_SSTATUS, SR_VS);
> @@ -31,11 +53,86 @@ static __always_inline void riscv_v_disable(void)
>  	csr_clear(CSR_SSTATUS, SR_VS);
>  }
>  
> +static __always_inline void __vstate_csr_save(struct __riscv_v_ext_state *dest)
> +{
> +	asm volatile (
> +		"csrr	%0, " __stringify(CSR_VSTART) "\n\t"
> +		"csrr	%1, " __stringify(CSR_VTYPE) "\n\t"
> +		"csrr	%2, " __stringify(CSR_VL) "\n\t"
> +		"csrr	%3, " __stringify(CSR_VCSR) "\n\t"
> +		: "=r" (dest->vstart), "=r" (dest->vtype), "=r" (dest->vl),
> +		  "=r" (dest->vcsr) : :);
> +}
> +
> +static __always_inline void __vstate_csr_restore(struct __riscv_v_ext_state *src)
> +{
> +	asm volatile (
> +		".option push\n\t"
> +		".option arch, +v\n\t"
> +		"vsetvl	 x0, %2, %1\n\t"
> +		".option pop\n\t"
> +		"csrw	" __stringify(CSR_VSTART) ", %0\n\t"
> +		"csrw	" __stringify(CSR_VCSR) ", %3\n\t"
> +		: : "r" (src->vstart), "r" (src->vtype), "r" (src->vl),
> +		    "r" (src->vcsr) :);
> +}
> +
> +static inline void __riscv_v_vstate_save(struct __riscv_v_ext_state *save_to,
> +					 void *datap)
> +{
> +	unsigned long vl;
> +
> +	riscv_v_enable();
> +	__vstate_csr_save(save_to);
> +	asm volatile (
> +		".option push\n\t"
> +		".option arch, +v\n\t"
> +		"vsetvli	%0, x0, e8, m8, ta, ma\n\t"
> +		"vse8.v		v0, (%1)\n\t"
> +		"add		%1, %1, %0\n\t"
> +		"vse8.v		v8, (%1)\n\t"
> +		"add		%1, %1, %0\n\t"
> +		"vse8.v		v16, (%1)\n\t"
> +		"add		%1, %1, %0\n\t"
> +		"vse8.v		v24, (%1)\n\t"
> +		".option pop\n\t"
> +		: "=&r" (vl) : "r" (datap) : "memory");
> +	riscv_v_disable();
> +}
> +
> +static inline void __riscv_v_vstate_restore(struct __riscv_v_ext_state *restore_from,
> +					    void *datap)
> +{
> +	unsigned long vl;
> +
> +	riscv_v_enable();
> +	asm volatile (
> +		".option push\n\t"
> +		".option arch, +v\n\t"
> +		"vsetvli	%0, x0, e8, m8, ta, ma\n\t"
> +		"vle8.v		v0, (%1)\n\t"
> +		"add		%1, %1, %0\n\t"
> +		"vle8.v		v8, (%1)\n\t"
> +		"add		%1, %1, %0\n\t"
> +		"vle8.v		v16, (%1)\n\t"
> +		"add		%1, %1, %0\n\t"
> +		"vle8.v		v24, (%1)\n\t"
> +		".option pop\n\t"
> +		: "=&r" (vl) : "r" (datap) : "memory");
> +	__vstate_csr_restore(restore_from);
> +	riscv_v_disable();
> +}
> +
>  #else /* ! CONFIG_RISCV_ISA_V  */
>  
> +struct pt_regs;
> +
>  static __always_inline bool has_vector(void) { return false; }
> +static inline bool riscv_v_vstate_query(struct pt_regs *regs) { return false; }
>  #define riscv_v_vsize (0)
>  #define riscv_v_setup_vsize()	 		do {} while (0)
> +#define riscv_v_vstate_off(regs)		do {} while (0)
> +#define riscv_v_vstate_on(regs)			do {} while (0)
>  
>  #endif /* CONFIG_RISCV_ISA_V */
>  
> diff --git a/arch/riscv/include/uapi/asm/ptrace.h b/arch/riscv/include/uapi/asm/ptrace.h
> index 882547f6bd5c..586786d023c4 100644
> --- a/arch/riscv/include/uapi/asm/ptrace.h
> +++ b/arch/riscv/include/uapi/asm/ptrace.h
> @@ -77,6 +77,23 @@ union __riscv_fp_state {
>  	struct __riscv_q_ext_state q;
>  };
>  
> +struct __riscv_v_ext_state {
> +	unsigned long vstart;
> +	unsigned long vl;
> +	unsigned long vtype;
> +	unsigned long vcsr;
> +	void *datap;
> +	/*
> +	 * In signal handler, datap will be set a correct user stack offset
> +	 * and vector registers will be copied to the address of datap
> +	 * pointer.
> +	 *
> +	 * In ptrace syscall, datap will be set to zero and the vector
> +	 * registers will be copied to the address right after this
> +	 * structure.
> +	 */
> +};
> +
>  #endif /* __ASSEMBLY__ */
>  
>  #endif /* _UAPI_ASM_RISCV_PTRACE_H */
> -- 
> 2.17.1
> 
>

Andy Chiu March 20, 2023, 2:46 p.m. UTC | #2

On Mon, Mar 20, 2023 at 9:05 PM Conor Dooley <[e-mail]> wrote:
>
> On Fri, Mar 17, 2023 at 11:35:27AM +0000, Andy Chiu wrote:
> > From: Greentime Hu <[e-mail]>
> >
> > Add vector state context struct to be added later in thread_struct. And
> > prepare low-level helper functions to save/restore vector contexts.
> >
> > This include Vector Regfile and CSRs holding dynamic configuration state
> > (vstart, vl, vtype, vcsr). The Vec Register width could be implementation
> > defined, but same for all processes, so that is saved separately.
> >
> > This is not yet wired into final thread_struct - will be done when
> > __switch_to actually starts doing this in later patches.
> >
> > Given the variable (and potentially large) size of regfile, they are
> > saved in dynamically allocated memory, pointed to by datap pointer in
> > __riscv_v_ext_state.
> >
> > Co-developed-by: Vincent Chen <[e-mail]>
> > Signed-off-by: Vincent Chen <[e-mail]>
> > Signed-off-by: Greentime Hu <[e-mail]>
> > Signed-off-by: Vineet Gupta <[e-mail]>
> > Signed-off-by: Andy Chiu <[e-mail]>
>
> I think you missed a:
> Acked-by: Conor Dooley <[e-mail]>
>
> Thanks,
> Conor.
>

Yes, removed it on purpose because I changed some inline assembly in
this submission. So I think you may want to take a look in case I did
something silly.

Thanks,
Andy.

Conor Dooley March 20, 2023, 2:54 p.m. UTC | #3

On Mon, Mar 20, 2023 at 10:46:57PM +0800, Andy Chiu wrote:
> On Mon, Mar 20, 2023 at 9:05 PM Conor Dooley <[e-mail]> wrote:
> >
> > On Fri, Mar 17, 2023 at 11:35:27AM +0000, Andy Chiu wrote:
> > > From: Greentime Hu <[e-mail]>
> > >
> > > Add vector state context struct to be added later in thread_struct. And
> > > prepare low-level helper functions to save/restore vector contexts.
> > >
> > > This include Vector Regfile and CSRs holding dynamic configuration state
> > > (vstart, vl, vtype, vcsr). The Vec Register width could be implementation
> > > defined, but same for all processes, so that is saved separately.
> > >
> > > This is not yet wired into final thread_struct - will be done when
> > > __switch_to actually starts doing this in later patches.
> > >
> > > Given the variable (and potentially large) size of regfile, they are
> > > saved in dynamically allocated memory, pointed to by datap pointer in
> > > __riscv_v_ext_state.
> > >
> > > Co-developed-by: Vincent Chen <[e-mail]>
> > > Signed-off-by: Vincent Chen <[e-mail]>
> > > Signed-off-by: Greentime Hu <[e-mail]>
> > > Signed-off-by: Vineet Gupta <[e-mail]>
> > > Signed-off-by: Andy Chiu <[e-mail]>
> >
> > I think you missed a:
> > Acked-by: Conor Dooley <[e-mail]>
> >
> > Thanks,
> > Conor.
> >
> 
> Yes, removed it on purpose because I changed some inline assembly in
> this submission. So I think you may want to take a look in case I did
> something silly.

Heh, inline asm is usually why I do "acked-by" rather than "reviewed-by"
as I am not particular confident in that realm ;)
No harm in being careful and dropping tags I suppose!

Guo Ren March 22, 2023, 1:54 a.m. UTC | #4

On Fri, Mar 17, 2023 at 7:37 PM Andy Chiu <[e-mail]> wrote:
>
> From: Greentime Hu <[e-mail]>
>
> Add vector state context struct to be added later in thread_struct. And
> prepare low-level helper functions to save/restore vector contexts.
>
> This include Vector Regfile and CSRs holding dynamic configuration state
> (vstart, vl, vtype, vcsr). The Vec Register width could be implementation
> defined, but same for all processes, so that is saved separately.
>
> This is not yet wired into final thread_struct - will be done when
> __switch_to actually starts doing this in later patches.
>
> Given the variable (and potentially large) size of regfile, they are
> saved in dynamically allocated memory, pointed to by datap pointer in
> __riscv_v_ext_state.
>
> Co-developed-by: Vincent Chen <[e-mail]>
> Signed-off-by: Vincent Chen <[e-mail]>
> Signed-off-by: Greentime Hu <[e-mail]>
> Signed-off-by: Vineet Gupta <[e-mail]>
> Signed-off-by: Andy Chiu <[e-mail]>
> ---
>  arch/riscv/include/asm/vector.h      | 97 ++++++++++++++++++++++++++++
>  arch/riscv/include/uapi/asm/ptrace.h | 17 +++++
>  2 files changed, 114 insertions(+)
>
> diff --git a/arch/riscv/include/asm/vector.h b/arch/riscv/include/asm/vector.h
> index 18448e24d77b..c7143b7d64d1 100644
> --- a/arch/riscv/include/asm/vector.h
> +++ b/arch/riscv/include/asm/vector.h
> @@ -10,8 +10,10 @@
>
>  #ifdef CONFIG_RISCV_ISA_V
>
> +#include <linux/stringify.h>
>  #include <asm/hwcap.h>
>  #include <asm/csr.h>
> +#include <asm/asm.h>
>
>  extern unsigned long riscv_v_vsize;
>  void riscv_v_setup_vsize(void);
> @@ -21,6 +23,26 @@ static __always_inline bool has_vector(void)
>         return riscv_has_extension_likely(RISCV_ISA_EXT_v);
>  }
>
> +static inline void __riscv_v_vstate_clean(struct pt_regs *regs)
> +{
> +       regs->status = (regs->status & ~SR_VS) | SR_VS_CLEAN;
> +}
> +
> +static inline void riscv_v_vstate_off(struct pt_regs *regs)
> +{
> +       regs->status = (regs->status & ~SR_VS) | SR_VS_OFF;
> +}
> +
> +static inline void riscv_v_vstate_on(struct pt_regs *regs)
> +{
> +       regs->status = (regs->status & ~SR_VS) | SR_VS_INITIAL;
> +}
> +
> +static inline bool riscv_v_vstate_query(struct pt_regs *regs)
> +{
> +       return (regs->status & SR_VS) != 0;
> +}
> +
>  static __always_inline void riscv_v_enable(void)
>  {
>         csr_set(CSR_SSTATUS, SR_VS);
> @@ -31,11 +53,86 @@ static __always_inline void riscv_v_disable(void)
>         csr_clear(CSR_SSTATUS, SR_VS);
>  }
>
> +static __always_inline void __vstate_csr_save(struct __riscv_v_ext_state *dest)
> +{
> +       asm volatile (
> +               "csrr   %0, " __stringify(CSR_VSTART) "\n\t"
> +               "csrr   %1, " __stringify(CSR_VTYPE) "\n\t"
> +               "csrr   %2, " __stringify(CSR_VL) "\n\t"
> +               "csrr   %3, " __stringify(CSR_VCSR) "\n\t"
> +               : "=r" (dest->vstart), "=r" (dest->vtype), "=r" (dest->vl),
> +                 "=r" (dest->vcsr) : :);
> +}
> +
> +static __always_inline void __vstate_csr_restore(struct __riscv_v_ext_state *src)
> +{
> +       asm volatile (
> +               ".option push\n\t"
> +               ".option arch, +v\n\t"
> +               "vsetvl  x0, %2, %1\n\t"
> +               ".option pop\n\t"
> +               "csrw   " __stringify(CSR_VSTART) ", %0\n\t"
> +               "csrw   " __stringify(CSR_VCSR) ", %3\n\t"
> +               : : "r" (src->vstart), "r" (src->vtype), "r" (src->vl),
> +                   "r" (src->vcsr) :);
> +}
> +
> +static inline void __riscv_v_vstate_save(struct __riscv_v_ext_state *save_to,
> +                                        void *datap)
> +{
> +       unsigned long vl;
> +
> +       riscv_v_enable();
> +       __vstate_csr_save(save_to);
> +       asm volatile (
> +               ".option push\n\t"
> +               ".option arch, +v\n\t"
> +               "vsetvli        %0, x0, e8, m8, ta, ma\n\t"
> +               "vse8.v         v0, (%1)\n\t"
> +               "add            %1, %1, %0\n\t"
> +               "vse8.v         v8, (%1)\n\t"
> +               "add            %1, %1, %0\n\t"
> +               "vse8.v         v16, (%1)\n\t"
> +               "add            %1, %1, %0\n\t"
> +               "vse8.v         v24, (%1)\n\t"
> +               ".option pop\n\t"
> +               : "=&r" (vl) : "r" (datap) : "memory");
> +       riscv_v_disable();
> +}
> +
> +static inline void __riscv_v_vstate_restore(struct __riscv_v_ext_state *restore_from,
> +                                           void *datap)
> +{
> +       unsigned long vl;
> +
> +       riscv_v_enable();
> +       asm volatile (
> +               ".option push\n\t"
> +               ".option arch, +v\n\t"
> +               "vsetvli        %0, x0, e8, m8, ta, ma\n\t"
> +               "vle8.v         v0, (%1)\n\t"
> +               "add            %1, %1, %0\n\t"
> +               "vle8.v         v8, (%1)\n\t"
> +               "add            %1, %1, %0\n\t"
> +               "vle8.v         v16, (%1)\n\t"
> +               "add            %1, %1, %0\n\t"
> +               "vle8.v         v24, (%1)\n\t"
> +               ".option pop\n\t"
> +               : "=&r" (vl) : "r" (datap) : "memory");
> +       __vstate_csr_restore(restore_from);
> +       riscv_v_disable();
> +}
> +
>  #else /* ! CONFIG_RISCV_ISA_V  */
>
> +struct pt_regs;
> +
>  static __always_inline bool has_vector(void) { return false; }
> +static inline bool riscv_v_vstate_query(struct pt_regs *regs) { return false; }
>  #define riscv_v_vsize (0)
>  #define riscv_v_setup_vsize()                  do {} while (0)
> +#define riscv_v_vstate_off(regs)               do {} while (0)
> +#define riscv_v_vstate_on(regs)                        do {} while (0)
>
>  #endif /* CONFIG_RISCV_ISA_V */
>
> diff --git a/arch/riscv/include/uapi/asm/ptrace.h b/arch/riscv/include/uapi/asm/ptrace.h
> index 882547f6bd5c..586786d023c4 100644
> --- a/arch/riscv/include/uapi/asm/ptrace.h
> +++ b/arch/riscv/include/uapi/asm/ptrace.h
> @@ -77,6 +77,23 @@ union __riscv_fp_state {
>         struct __riscv_q_ext_state q;
>  };
>
> +struct __riscv_v_ext_state {
> +       unsigned long vstart;
> +       unsigned long vl;
> +       unsigned long vtype;
> +       unsigned long vcsr;
> +       void *datap;
> +       /*
> +        * In signal handler, datap will be set a correct user stack offset
> +        * and vector registers will be copied to the address of datap
> +        * pointer.
> +        *
> +        * In ptrace syscall, datap will be set to zero and the vector
> +        * registers will be copied to the address right after this
> +        * structure.
> +        */
> +};
> +
>  #endif /* __ASSEMBLY__ */
>
>  #endif /* _UAPI_ASM_RISCV_PTRACE_H */
Reviewed-by: Guo Ren <[e-mail]>

> --
> 2.17.1
>

Björn Töpel March 23, 2023, 10:21 a.m. UTC | #5

Andy Chiu <[e-mail]> writes:

> From: Greentime Hu <[e-mail]>
>
> Add vector state context struct to be added later in thread_struct. And
> prepare low-level helper functions to save/restore vector contexts.
>
> This include Vector Regfile and CSRs holding dynamic configuration state
> (vstart, vl, vtype, vcsr). The Vec Register width could be implementation
> defined, but same for all processes, so that is saved separately.
>
> This is not yet wired into final thread_struct - will be done when
> __switch_to actually starts doing this in later patches.
>
> Given the variable (and potentially large) size of regfile, they are
> saved in dynamically allocated memory, pointed to by datap pointer in
> __riscv_v_ext_state.
>
> Co-developed-by: Vincent Chen <[e-mail]>
> Signed-off-by: Vincent Chen <[e-mail]>
> Signed-off-by: Greentime Hu <[e-mail]>
> Signed-off-by: Vineet Gupta <[e-mail]>
> Signed-off-by: Andy Chiu <[e-mail]>

Thank you for doing the scratch reg change!

Reviewed-by: Björn Töpel <[e-mail]>

Patch

diff --git a/arch/riscv/include/asm/vector.h b/arch/riscv/include/asm/vector.h
index 18448e24d77b..c7143b7d64d1 100644
--- a/arch/riscv/include/asm/vector.h
+++ b/arch/riscv/include/asm/vector.h
@@ -10,8 +10,10 @@ 
 
 #ifdef CONFIG_RISCV_ISA_V
 
+#include <linux/stringify.h>
 #include <asm/hwcap.h>
 #include <asm/csr.h>
+#include <asm/asm.h>
 
 extern unsigned long riscv_v_vsize;
 void riscv_v_setup_vsize(void);
@@ -21,6 +23,26 @@  static __always_inline bool has_vector(void)
 	return riscv_has_extension_likely(RISCV_ISA_EXT_v);
 }
 
+static inline void __riscv_v_vstate_clean(struct pt_regs *regs)
+{
+	regs->status = (regs->status & ~SR_VS) | SR_VS_CLEAN;
+}
+
+static inline void riscv_v_vstate_off(struct pt_regs *regs)
+{
+	regs->status = (regs->status & ~SR_VS) | SR_VS_OFF;
+}
+
+static inline void riscv_v_vstate_on(struct pt_regs *regs)
+{
+	regs->status = (regs->status & ~SR_VS) | SR_VS_INITIAL;
+}
+
+static inline bool riscv_v_vstate_query(struct pt_regs *regs)
+{
+	return (regs->status & SR_VS) != 0;
+}
+
 static __always_inline void riscv_v_enable(void)
 {
 	csr_set(CSR_SSTATUS, SR_VS);
@@ -31,11 +53,86 @@  static __always_inline void riscv_v_disable(void)
 	csr_clear(CSR_SSTATUS, SR_VS);
 }
 
+static __always_inline void __vstate_csr_save(struct __riscv_v_ext_state *dest)
+{
+	asm volatile (
+		"csrr	%0, " __stringify(CSR_VSTART) "\n\t"
+		"csrr	%1, " __stringify(CSR_VTYPE) "\n\t"
+		"csrr	%2, " __stringify(CSR_VL) "\n\t"
+		"csrr	%3, " __stringify(CSR_VCSR) "\n\t"
+		: "=r" (dest->vstart), "=r" (dest->vtype), "=r" (dest->vl),
+		  "=r" (dest->vcsr) : :);
+}
+
+static __always_inline void __vstate_csr_restore(struct __riscv_v_ext_state *src)
+{
+	asm volatile (
+		".option push\n\t"
+		".option arch, +v\n\t"
+		"vsetvl	 x0, %2, %1\n\t"
+		".option pop\n\t"
+		"csrw	" __stringify(CSR_VSTART) ", %0\n\t"
+		"csrw	" __stringify(CSR_VCSR) ", %3\n\t"
+		: : "r" (src->vstart), "r" (src->vtype), "r" (src->vl),
+		    "r" (src->vcsr) :);
+}
+
+static inline void __riscv_v_vstate_save(struct __riscv_v_ext_state *save_to,
+					 void *datap)
+{
+	unsigned long vl;
+
+	riscv_v_enable();
+	__vstate_csr_save(save_to);
+	asm volatile (
+		".option push\n\t"
+		".option arch, +v\n\t"
+		"vsetvli	%0, x0, e8, m8, ta, ma\n\t"
+		"vse8.v		v0, (%1)\n\t"
+		"add		%1, %1, %0\n\t"
+		"vse8.v		v8, (%1)\n\t"
+		"add		%1, %1, %0\n\t"
+		"vse8.v		v16, (%1)\n\t"
+		"add		%1, %1, %0\n\t"
+		"vse8.v		v24, (%1)\n\t"
+		".option pop\n\t"
+		: "=&r" (vl) : "r" (datap) : "memory");
+	riscv_v_disable();
+}
+
+static inline void __riscv_v_vstate_restore(struct __riscv_v_ext_state *restore_from,
+					    void *datap)
+{
+	unsigned long vl;
+
+	riscv_v_enable();
+	asm volatile (
+		".option push\n\t"
+		".option arch, +v\n\t"
+		"vsetvli	%0, x0, e8, m8, ta, ma\n\t"
+		"vle8.v		v0, (%1)\n\t"
+		"add		%1, %1, %0\n\t"
+		"vle8.v		v8, (%1)\n\t"
+		"add		%1, %1, %0\n\t"
+		"vle8.v		v16, (%1)\n\t"
+		"add		%1, %1, %0\n\t"
+		"vle8.v		v24, (%1)\n\t"
+		".option pop\n\t"
+		: "=&r" (vl) : "r" (datap) : "memory");
+	__vstate_csr_restore(restore_from);
+	riscv_v_disable();
+}
+
 #else /* ! CONFIG_RISCV_ISA_V  */
 
+struct pt_regs;
+
 static __always_inline bool has_vector(void) { return false; }
+static inline bool riscv_v_vstate_query(struct pt_regs *regs) { return false; }
 #define riscv_v_vsize (0)
 #define riscv_v_setup_vsize()	 		do {} while (0)
+#define riscv_v_vstate_off(regs)		do {} while (0)
+#define riscv_v_vstate_on(regs)			do {} while (0)
 
 #endif /* CONFIG_RISCV_ISA_V */
 
diff --git a/arch/riscv/include/uapi/asm/ptrace.h b/arch/riscv/include/uapi/asm/ptrace.h
index 882547f6bd5c..586786d023c4 100644
--- a/arch/riscv/include/uapi/asm/ptrace.h
+++ b/arch/riscv/include/uapi/asm/ptrace.h
@@ -77,6 +77,23 @@  union __riscv_fp_state {
 	struct __riscv_q_ext_state q;
 };
 
+struct __riscv_v_ext_state {
+	unsigned long vstart;
+	unsigned long vl;
+	unsigned long vtype;
+	unsigned long vcsr;
+	void *datap;
+	/*
+	 * In signal handler, datap will be set a correct user stack offset
+	 * and vector registers will be copied to the address of datap
+	 * pointer.
+	 *
+	 * In ptrace syscall, datap will be set to zero and the vector
+	 * registers will be copied to the address right after this
+	 * structure.
+	 */
+};
+
 #endif /* __ASSEMBLY__ */
 
 #endif /* _UAPI_ASM_RISCV_PTRACE_H */