On 11/03/2019 07:57, Chao Gao wrote:
> to replace the current per-cpu cache 'uci->mc'.
>
> Compared to the current per-cpu cache, the benefits of the global
> microcode cache are:
> 1. It reduces the work that need to be done on each CPU. Parsing ucode
> file is done once on one CPU. Other CPUs needn't parse ucode file.
> Instead, they can find out and load the newest patch from the global
> cache.
> 2. It reduces the memory consumption on a system with many CPU cores.
>
> Two functions, microcode_save_patch() and microcode_find_patch() are
> introduced. The former adds one given patch to the global cache. The
> latter gets a newer and matched ucode patch from the global cache.
> All operations on the cache is expected to be done with the
> 'microcode_mutex' hold.
>
> Note that I deliberately avoid touching 'uci->mc' as I am going to
> remove it completely in the next patch.
>
> Signed-off-by: Chao Gao <chao....@intel.com>
> ---
> Changes in v6:
> - constify local variables and function parameters if possible
> - comment that the global cache is protected by 'microcode_mutex'.
> and add assertions to catch violations in microcode_{save/find}_patch()
>
> Changes in v5:
> - reword the commit description
> - find_patch() and save_patch() are abstracted into common functions
> with some hooks for AMD and Intel
> ---
> xen/arch/x86/microcode.c | 60 +++++++++++++++++++++++++++
> xen/arch/x86/microcode_amd.c | 91
> +++++++++++++++++++++++++++++++++++++----
> xen/arch/x86/microcode_intel.c | 66 ++++++++++++++++++++++++++----
> xen/include/asm-x86/microcode.h | 13 ++++++
> 4 files changed, 215 insertions(+), 15 deletions(-)
This needs the following change for the AMD part:
diff --git a/xen/arch/x86/microcode_amd.c b/xen/arch/x86/microcode_amd.c
index 4aa8fdca38..358f3c44e3 100644
--- a/xen/arch/x86/microcode_amd.c
+++ b/xen/arch/x86/microcode_amd.c
@@ -249,6 +249,7 @@ static enum microcode_match_result compare_patch(
static int apply_microcode(void)
{
uint32_t rev;
+ struct microcode_amd *mc_amd;
const struct microcode_header_amd *hdr;
const struct microcode_patch *patch;
int hw_err;
@@ -259,7 +260,8 @@ static int apply_microcode(void)
if ( patch == NULL )
return -EINVAL;
- hdr = patch->data;
+ mc_amd = patch->data;
+ hdr = mc_amd->mpb;
BUG_ON(local_irq_is_enabled());
Another thing to mention is that even with this fix applied, I get
early ucode update only on CPU0. With the whole series applied, secondary
CPUs also start doing early ucode update.
--
Thanks,
Sergey
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