diff mbox series

[v19,004/130] x86/virt/tdx: Support global metadata read for all element sizes

Message ID db0a8b2fb7138021fed7d740c84bd663025f4451.1708933498.git.isaku.yamahata@intel.com
State New
Headers
Series [v19,001/130] x86/virt/tdx: Rename _offset to _member for TD_SYSINFO_MAP() macro |

Commit Message

Isaku Yamahata Feb. 26, 2024, 8:25 a.m. UTC 
  From: Kai Huang <kai.huang@intel.com>

For now the kernel only reads TDMR related global metadata fields for
module initialization.  All these fields are 16-bits, and the kernel
only supports reading 16-bits fields.

KVM will need to read a bunch of non-TDMR related metadata to create and
run TDX guests.  It's essential to provide a generic metadata read
infrastructure which supports reading all 8/16/32/64 bits element sizes.

Extend the metadata read to support reading all these element sizes.

Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
---
 arch/x86/virt/vmx/tdx/tdx.c | 59 +++++++++++++++++++++++++------------
 arch/x86/virt/vmx/tdx/tdx.h |  2 --
 2 files changed, 40 insertions(+), 21 deletions(-)

Comments

Juergen Gross Feb. 26, 2024, 2:32 p.m. UTC | #1 
On 26.02.24 09:25, isaku.yamahata@intel.com wrote:
> From: Kai Huang <kai.huang@intel.com>
> 
> For now the kernel only reads TDMR related global metadata fields for
> module initialization.  All these fields are 16-bits, and the kernel
> only supports reading 16-bits fields.
> 
> KVM will need to read a bunch of non-TDMR related metadata to create and
> run TDX guests.  It's essential to provide a generic metadata read
> infrastructure which supports reading all 8/16/32/64 bits element sizes.
> 
> Extend the metadata read to support reading all these element sizes.
> 
> Signed-off-by: Kai Huang <kai.huang@intel.com>
> Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
> ---
>   arch/x86/virt/vmx/tdx/tdx.c | 59 +++++++++++++++++++++++++------------
>   arch/x86/virt/vmx/tdx/tdx.h |  2 --
>   2 files changed, 40 insertions(+), 21 deletions(-)
> 
> diff --git a/arch/x86/virt/vmx/tdx/tdx.c b/arch/x86/virt/vmx/tdx/tdx.c
> index eb208da4ff63..a19adc898df6 100644
> --- a/arch/x86/virt/vmx/tdx/tdx.c
> +++ b/arch/x86/virt/vmx/tdx/tdx.c
> @@ -271,23 +271,35 @@ static int read_sys_metadata_field(u64 field_id, u64 *data)
>   	return 0;
>   }
>   
> -static int read_sys_metadata_field16(u64 field_id,
> -				     int offset,
> -				     void *stbuf)
> +/* Return the metadata field element size in bytes */
> +static int get_metadata_field_bytes(u64 field_id)
>   {
> -	u16 *st_member = stbuf + offset;
> +	/*
> +	 * TDX supports 8/16/32/64 bits metadata field element sizes.
> +	 * TDX module determines the metadata element size based on the
> +	 * "element size code" encoded in the field ID (see the comment
> +	 * of MD_FIELD_ID_ELE_SIZE_CODE macro for specific encodings).
> +	 */
> +	return 1 << MD_FIELD_ID_ELE_SIZE_CODE(field_id);
> +}
> +
> +static int stbuf_read_sys_metadata_field(u64 field_id,
> +					 int offset,
> +					 int bytes,
> +					 void *stbuf)
> +{
> +	void *st_member = stbuf + offset;
>   	u64 tmp;
>   	int ret;
>   
> -	if (WARN_ON_ONCE(MD_FIELD_ID_ELE_SIZE_CODE(field_id) !=
> -			MD_FIELD_ID_ELE_SIZE_16BIT))
> +	if (WARN_ON_ONCE(get_metadata_field_bytes(field_id) != bytes))
>   		return -EINVAL;
>   
>   	ret = read_sys_metadata_field(field_id, &tmp);
>   	if (ret)
>   		return ret;
>   
> -	*st_member = tmp;
> +	memcpy(st_member, &tmp, bytes);
>   
>   	return 0;
>   }
> @@ -295,11 +307,30 @@ static int read_sys_metadata_field16(u64 field_id,
>   struct field_mapping {
>   	u64 field_id;
>   	int offset;
> +	int size;
>   };
>   
>   #define TD_SYSINFO_MAP(_field_id, _struct, _member)	\
>   	{ .field_id = MD_FIELD_ID_##_field_id,		\
> -	  .offset   = offsetof(_struct, _member) }
> +	  .offset   = offsetof(_struct, _member),	\
> +	  .size     = sizeof(typeof(((_struct *)0)->_member)) }
> +
> +static int read_sys_metadata(struct field_mapping *fields, int nr_fields,

The first parameter should be "const struct field_mapping *fields".


Juergen
Kai Huang Feb. 27, 2024, 8:40 a.m. UTC | #2 
On Mon, 2024-02-26 at 15:32 +0100, Juergen Gross wrote:
> On 26.02.24 09:25, isaku.yamahata@intel.com wrote:
> > From: Kai Huang <kai.huang@intel.com>
> > 
> > For now the kernel only reads TDMR related global metadata fields for
> > module initialization.  All these fields are 16-bits, and the kernel
> > only supports reading 16-bits fields.
> > 
> > KVM will need to read a bunch of non-TDMR related metadata to create and
> > run TDX guests.  It's essential to provide a generic metadata read
> > infrastructure which supports reading all 8/16/32/64 bits element sizes.
> > 
> > Extend the metadata read to support reading all these element sizes.
> > 
> > Signed-off-by: Kai Huang <kai.huang@intel.com>
> > Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
> > ---
> >   arch/x86/virt/vmx/tdx/tdx.c | 59 +++++++++++++++++++++++++------------
> >   arch/x86/virt/vmx/tdx/tdx.h |  2 --
> >   2 files changed, 40 insertions(+), 21 deletions(-)
> > 
> > diff --git a/arch/x86/virt/vmx/tdx/tdx.c b/arch/x86/virt/vmx/tdx/tdx.c
> > index eb208da4ff63..a19adc898df6 100644
> > --- a/arch/x86/virt/vmx/tdx/tdx.c
> > +++ b/arch/x86/virt/vmx/tdx/tdx.c
> > @@ -271,23 +271,35 @@ static int read_sys_metadata_field(u64 field_id, u64 *data)
> >   	return 0;
> >   }
> >   
> > -static int read_sys_metadata_field16(u64 field_id,
> > -				     int offset,
> > -				     void *stbuf)
> > +/* Return the metadata field element size in bytes */
> > +static int get_metadata_field_bytes(u64 field_id)
> >   {
> > -	u16 *st_member = stbuf + offset;
> > +	/*
> > +	 * TDX supports 8/16/32/64 bits metadata field element sizes.
> > +	 * TDX module determines the metadata element size based on the
> > +	 * "element size code" encoded in the field ID (see the comment
> > +	 * of MD_FIELD_ID_ELE_SIZE_CODE macro for specific encodings).
> > +	 */
> > +	return 1 << MD_FIELD_ID_ELE_SIZE_CODE(field_id);
> > +}
> > +
> > +static int stbuf_read_sys_metadata_field(u64 field_id,
> > +					 int offset,
> > +					 int bytes,
> > +					 void *stbuf)
> > +{
> > +	void *st_member = stbuf + offset;
> >   	u64 tmp;
> >   	int ret;
> >   
> > -	if (WARN_ON_ONCE(MD_FIELD_ID_ELE_SIZE_CODE(field_id) !=
> > -			MD_FIELD_ID_ELE_SIZE_16BIT))
> > +	if (WARN_ON_ONCE(get_metadata_field_bytes(field_id) != bytes))
> >   		return -EINVAL;
> >   
> >   	ret = read_sys_metadata_field(field_id, &tmp);
> >   	if (ret)
> >   		return ret;
> >   
> > -	*st_member = tmp;
> > +	memcpy(st_member, &tmp, bytes);
> >   
> >   	return 0;
> >   }
> > @@ -295,11 +307,30 @@ static int read_sys_metadata_field16(u64 field_id,
> >   struct field_mapping {
> >   	u64 field_id;
> >   	int offset;
> > +	int size;
> >   };
> >   
> >   #define TD_SYSINFO_MAP(_field_id, _struct, _member)	\
> >   	{ .field_id = MD_FIELD_ID_##_field_id,		\
> > -	  .offset   = offsetof(_struct, _member) }
> > +	  .offset   = offsetof(_struct, _member),	\
> > +	  .size     = sizeof(typeof(((_struct *)0)->_member)) }
> > +
> > +static int read_sys_metadata(struct field_mapping *fields, int nr_fields,
> 
> The first parameter should be "const struct field_mapping *fields".
> 
> 

Indeed. :-)
diff mbox series

Patch

diff --git a/arch/x86/virt/vmx/tdx/tdx.c b/arch/x86/virt/vmx/tdx/tdx.c
index eb208da4ff63..a19adc898df6 100644
--- a/arch/x86/virt/vmx/tdx/tdx.c
+++ b/arch/x86/virt/vmx/tdx/tdx.c
@@ -271,23 +271,35 @@  static int read_sys_metadata_field(u64 field_id, u64 *data)
 	return 0;
 }
 
-static int read_sys_metadata_field16(u64 field_id,
-				     int offset,
-				     void *stbuf)
+/* Return the metadata field element size in bytes */
+static int get_metadata_field_bytes(u64 field_id)
 {
-	u16 *st_member = stbuf + offset;
+	/*
+	 * TDX supports 8/16/32/64 bits metadata field element sizes.
+	 * TDX module determines the metadata element size based on the
+	 * "element size code" encoded in the field ID (see the comment
+	 * of MD_FIELD_ID_ELE_SIZE_CODE macro for specific encodings).
+	 */
+	return 1 << MD_FIELD_ID_ELE_SIZE_CODE(field_id);
+}
+
+static int stbuf_read_sys_metadata_field(u64 field_id,
+					 int offset,
+					 int bytes,
+					 void *stbuf)
+{
+	void *st_member = stbuf + offset;
 	u64 tmp;
 	int ret;
 
-	if (WARN_ON_ONCE(MD_FIELD_ID_ELE_SIZE_CODE(field_id) !=
-			MD_FIELD_ID_ELE_SIZE_16BIT))
+	if (WARN_ON_ONCE(get_metadata_field_bytes(field_id) != bytes))
 		return -EINVAL;
 
 	ret = read_sys_metadata_field(field_id, &tmp);
 	if (ret)
 		return ret;
 
-	*st_member = tmp;
+	memcpy(st_member, &tmp, bytes);
 
 	return 0;
 }
@@ -295,11 +307,30 @@  static int read_sys_metadata_field16(u64 field_id,
 struct field_mapping {
 	u64 field_id;
 	int offset;
+	int size;
 };
 
 #define TD_SYSINFO_MAP(_field_id, _struct, _member)	\
 	{ .field_id = MD_FIELD_ID_##_field_id,		\
-	  .offset   = offsetof(_struct, _member) }
+	  .offset   = offsetof(_struct, _member),	\
+	  .size     = sizeof(typeof(((_struct *)0)->_member)) }
+
+static int read_sys_metadata(struct field_mapping *fields, int nr_fields,
+			     void *stbuf)
+{
+	int i, ret;
+
+	for (i = 0; i < nr_fields; i++) {
+		ret = stbuf_read_sys_metadata_field(fields[i].field_id,
+				      fields[i].offset,
+				      fields[i].size,
+				      stbuf);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
 
 #define TD_SYSINFO_MAP_TDMR_INFO(_field_id, _member)	\
 	TD_SYSINFO_MAP(_field_id, struct tdx_tdmr_sysinfo, _member)
@@ -314,19 +345,9 @@  static int get_tdx_tdmr_sysinfo(struct tdx_tdmr_sysinfo *tdmr_sysinfo)
 		TD_SYSINFO_MAP_TDMR_INFO(PAMT_2M_ENTRY_SIZE,    pamt_entry_size[TDX_PS_2M]),
 		TD_SYSINFO_MAP_TDMR_INFO(PAMT_1G_ENTRY_SIZE,    pamt_entry_size[TDX_PS_1G]),
 	};
-	int ret;
-	int i;
 
 	/* Populate 'tdmr_sysinfo' fields using the mapping structure above: */
-	for (i = 0; i < ARRAY_SIZE(fields); i++) {
-		ret = read_sys_metadata_field16(fields[i].field_id,
-						fields[i].offset,
-						tdmr_sysinfo);
-		if (ret)
-			return ret;
-	}
-
-	return 0;
+	return read_sys_metadata(fields, ARRAY_SIZE(fields), tdmr_sysinfo);
 }
 
 /* Calculate the actual TDMR size */
diff --git a/arch/x86/virt/vmx/tdx/tdx.h b/arch/x86/virt/vmx/tdx/tdx.h
index b701f69485d3..4c32c8bf156a 100644
--- a/arch/x86/virt/vmx/tdx/tdx.h
+++ b/arch/x86/virt/vmx/tdx/tdx.h
@@ -53,8 +53,6 @@ 
 #define MD_FIELD_ID_ELE_SIZE_CODE(_field_id)	\
 		(((_field_id) & GENMASK_ULL(33, 32)) >> 32)
 
-#define MD_FIELD_ID_ELE_SIZE_16BIT	1
-
 struct tdmr_reserved_area {
 	u64 offset;
 	u64 size;