Re: [Xen-devel] [PATCH 4/4] xen: Introduce a xmemdup_bytes() helper
Hi Andrew,
On 26/03/2020 14:53, Andrew Cooper wrote:
On 21/03/2020 22:19, Julien Grall wrote:
diff --git a/xen/include/xen/xmalloc.h b/xen/include/xen/xmalloc.h
index f515ceee2a..16979a117c 100644
--- a/xen/include/xen/xmalloc.h
+++ b/xen/include/xen/xmalloc.h
@@ -51,6 +51,17 @@
#define xmalloc_bytes(_bytes) _xmalloc(_bytes, SMP_CACHE_BYTES)
#define xzalloc_bytes(_bytes) _xzalloc(_bytes, SMP_CACHE_BYTES)
+/* Allocate untyped storage and copying an existing instance. */
+#define xmemdup_bytes(_src, _nr)\
+({ \
+unsigned long nr_ = (_nr); \
+void *dst_ = xmalloc_bytes(nr_);\
The nr_ vs _nr is really confusing to read. Could you re-implement the
function as a static inline?
I'd really prefer to, but sadly not.
That requires untangling headers sufficiently so we can include
string.h, to be able to use memcpy. I don't have time at the moment to
sort that out.
Ok :(. We will have to live with the macro for the time being then.
Acked-by: Julien Grall
Cheers,
--
Julien Grall
Re: [Xen-devel] [PATCH 4/4] xen: Introduce a xmemdup_bytes() helper
On 26.03.2020 16:38, Andrew Cooper wrote:
> On 23/03/2020 08:38, Jan Beulich wrote:
>> On 21.03.2020 23:19, Julien Grall wrote:
>>> On Fri, 20 Mar 2020 at 21:26, Andrew Cooper
>>> wrote:
--- a/xen/include/xen/xmalloc.h
+++ b/xen/include/xen/xmalloc.h
@@ -51,6 +51,17 @@
#define xmalloc_bytes(_bytes) _xmalloc(_bytes, SMP_CACHE_BYTES)
#define xzalloc_bytes(_bytes) _xzalloc(_bytes, SMP_CACHE_BYTES)
+/* Allocate untyped storage and copying an existing instance. */
+#define xmemdup_bytes(_src, _nr)\
+({ \
+unsigned long nr_ = (_nr); \
+void *dst_ = xmalloc_bytes(nr_);\
>>> The nr_ vs _nr is really confusing to read. Could you re-implement the
>>> function as a static inline?
>> And even if that wouldn't work out - what's the point of having
>> macro argument names with leading underscores?
>
> Consistency with all the other code in this file.
I value consistency quite high, but then please consistent with
something that properly follows other rules.
>> This isn't any
>> better standard-wise (afaict) than other uses of leading
>> underscores for identifiers which aren't CU-scope.
>
> It is a parameter describing textural replacement within the body.
> There is 0 interaction with external namespacing standards.
Please forgive me saying so, but a typical reply I might get back
from you would be: And?
I'm not going to insist nor nak the patch, but I don't welcome
widening existing issues we have.
Jan
Re: [Xen-devel] [PATCH 4/4] xen: Introduce a xmemdup_bytes() helper
On 23/03/2020 08:38, Jan Beulich wrote:
> On 21.03.2020 23:19, Julien Grall wrote:
>> On Fri, 20 Mar 2020 at 21:26, Andrew Cooper
>> wrote:
>>> --- a/xen/include/xen/xmalloc.h
>>> +++ b/xen/include/xen/xmalloc.h
>>> @@ -51,6 +51,17 @@
>>> #define xmalloc_bytes(_bytes) _xmalloc(_bytes, SMP_CACHE_BYTES)
>>> #define xzalloc_bytes(_bytes) _xzalloc(_bytes, SMP_CACHE_BYTES)
>>>
>>> +/* Allocate untyped storage and copying an existing instance. */
>>> +#define xmemdup_bytes(_src, _nr)\
>>> +({ \
>>> +unsigned long nr_ = (_nr); \
>>> +void *dst_ = xmalloc_bytes(nr_);\
>> The nr_ vs _nr is really confusing to read. Could you re-implement the
>> function as a static inline?
> And even if that wouldn't work out - what's the point of having
> macro argument names with leading underscores?
Consistency with all the other code in this file.
> This isn't any
> better standard-wise (afaict) than other uses of leading
> underscores for identifiers which aren't CU-scope.
It is a parameter describing textural replacement within the body.
There is 0 interaction with external namespacing standards.
~Andrew
Re: [Xen-devel] [PATCH 4/4] xen: Introduce a xmemdup_bytes() helper
On 21/03/2020 22:19, Julien Grall wrote:
>> diff --git a/xen/include/xen/xmalloc.h b/xen/include/xen/xmalloc.h
>> index f515ceee2a..16979a117c 100644
>> --- a/xen/include/xen/xmalloc.h
>> +++ b/xen/include/xen/xmalloc.h
>> @@ -51,6 +51,17 @@
>> #define xmalloc_bytes(_bytes) _xmalloc(_bytes, SMP_CACHE_BYTES)
>> #define xzalloc_bytes(_bytes) _xzalloc(_bytes, SMP_CACHE_BYTES)
>>
>> +/* Allocate untyped storage and copying an existing instance. */
>> +#define xmemdup_bytes(_src, _nr)\
>> +({ \
>> +unsigned long nr_ = (_nr); \
>> +void *dst_ = xmalloc_bytes(nr_);\
> The nr_ vs _nr is really confusing to read. Could you re-implement the
> function as a static inline?
I'd really prefer to, but sadly not.
That requires untangling headers sufficiently so we can include
string.h, to be able to use memcpy. I don't have time at the moment to
sort that out.
~Andrew
Re: [Xen-devel] [PATCH 4/4] xen: Introduce a xmemdup_bytes() helper
On 21.03.2020 23:19, Julien Grall wrote:
> On Fri, 20 Mar 2020 at 21:26, Andrew Cooper wrote:
>> --- a/xen/include/xen/xmalloc.h
>> +++ b/xen/include/xen/xmalloc.h
>> @@ -51,6 +51,17 @@
>> #define xmalloc_bytes(_bytes) _xmalloc(_bytes, SMP_CACHE_BYTES)
>> #define xzalloc_bytes(_bytes) _xzalloc(_bytes, SMP_CACHE_BYTES)
>>
>> +/* Allocate untyped storage and copying an existing instance. */
>> +#define xmemdup_bytes(_src, _nr)\
>> +({ \
>> +unsigned long nr_ = (_nr); \
>> +void *dst_ = xmalloc_bytes(nr_);\
>
> The nr_ vs _nr is really confusing to read. Could you re-implement the
> function as a static inline?
And even if that wouldn't work out - what's the point of having
macro argument names with leading underscores? This isn't any
better standard-wise (afaict) than other uses of leading
underscores for identifiers which aren't CU-scope.
Jan
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Re: [Xen-devel] [PATCH 4/4] xen: Introduce a xmemdup_bytes() helper
Hi Andrew,
On Fri, 20 Mar 2020 at 21:26, Andrew Cooper wrote:
>
> Use it to simplify the x86 microcode logic, taking the opportunity to drop the
> -ENOMEM printks.
>
> Signed-off-by: Andrew Cooper
> ---
> CC: Jan Beulich
> CC: Wei Liu
> CC: Roger Pau Monné
> ---
> xen/arch/x86/cpu/microcode/amd.c | 9 ++---
> xen/arch/x86/cpu/microcode/intel.c | 7 ++-
> xen/include/xen/xmalloc.h | 11 +++
I did notice a few times in the past months where only the x86 folks
where CCed even when there are changes in common code.
Even if I am mostly likely going to be happy with the changes, you
should at least give the other maintainers an opportunity to
object/comment.
May I ask to CC all the relevant maintainers in the future?
scripts/add_maintainers.pl should do the job for you.
> 3 files changed, 15 insertions(+), 12 deletions(-)
>
> diff --git a/xen/arch/x86/cpu/microcode/amd.c
> b/xen/arch/x86/cpu/microcode/amd.c
> index 0998a36b5c..12a3b6b32c 100644
> --- a/xen/arch/x86/cpu/microcode/amd.c
> +++ b/xen/arch/x86/cpu/microcode/amd.c
> @@ -299,11 +299,10 @@ static int get_ucode_from_buffer_amd(
> return -EINVAL;
> }
>
> -mc_amd->mpb = xmalloc_bytes(mpbuf->len);
> +mc_amd->mpb = xmemdup_bytes(mpbuf->data, mpbuf->len);
> if ( !mc_amd->mpb )
> return -ENOMEM;
> mc_amd->mpb_size = mpbuf->len;
> -memcpy(mc_amd->mpb, mpbuf->data, mpbuf->len);
>
> pr_debug("microcode: CPU%d size %zu, block size %u offset %zu equivID
> %#x rev %#x\n",
> smp_processor_id(), bufsize, mpbuf->len, *offset,
> @@ -336,14 +335,10 @@ static int install_equiv_cpu_table(
> return -EINVAL;
> }
>
> -mc_amd->equiv_cpu_table = xmalloc_bytes(mpbuf->len);
> +mc_amd->equiv_cpu_table = xmemdup_bytes(mpbuf->data, mpbuf->len);
> if ( !mc_amd->equiv_cpu_table )
> -{
> -printk(KERN_ERR "microcode: Cannot allocate memory for equivalent
> cpu table\n");
> return -ENOMEM;
> -}
>
> -memcpy(mc_amd->equiv_cpu_table, mpbuf->data, mpbuf->len);
> mc_amd->equiv_cpu_table_size = mpbuf->len;
>
> return 0;
> diff --git a/xen/arch/x86/cpu/microcode/intel.c
> b/xen/arch/x86/cpu/microcode/intel.c
> index 6ac5f98694..f26511da98 100644
> --- a/xen/arch/x86/cpu/microcode/intel.c
> +++ b/xen/arch/x86/cpu/microcode/intel.c
> @@ -339,13 +339,10 @@ static long get_next_ucode_from_buffer(struct
> microcode_intel **mc,
> return -EINVAL;
> }
>
> -*mc = xmalloc_bytes(total_size);
> +*mc = xmemdup_bytes(mc_header, total_size);
> if ( *mc == NULL )
> -{
> -printk(KERN_ERR "microcode: error! Can not allocate memory\n");
> return -ENOMEM;
> -}
> -memcpy(*mc, (const void *)(buf + offset), total_size);
> +
> return offset + total_size;
> }
>
> diff --git a/xen/include/xen/xmalloc.h b/xen/include/xen/xmalloc.h
> index f515ceee2a..16979a117c 100644
> --- a/xen/include/xen/xmalloc.h
> +++ b/xen/include/xen/xmalloc.h
> @@ -51,6 +51,17 @@
> #define xmalloc_bytes(_bytes) _xmalloc(_bytes, SMP_CACHE_BYTES)
> #define xzalloc_bytes(_bytes) _xzalloc(_bytes, SMP_CACHE_BYTES)
>
> +/* Allocate untyped storage and copying an existing instance. */
> +#define xmemdup_bytes(_src, _nr)\
> +({ \
> +unsigned long nr_ = (_nr); \
> +void *dst_ = xmalloc_bytes(nr_);\
The nr_ vs _nr is really confusing to read. Could you re-implement the
function as a static inline?
Cheers,
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Re: [Xen-devel] [PATCH 4/4] xen: Introduce a xmemdup_bytes() helper
On Fri, Mar 20, 2020 at 09:24:52PM +, Andrew Cooper wrote: > Use it to simplify the x86 microcode logic, taking the opportunity to drop the > -ENOMEM printks. > > Signed-off-by: Andrew Cooper Reviewed-by: Wei Liu ___ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
