[PATCH v4 3/7] x86/boot: Collect the Raw CPU Policy earlier on boot

Andrew Cooper posted 7 patches 5 months, 1 week ago
[PATCH v4 3/7] x86/boot: Collect the Raw CPU Policy earlier on boot
Posted by Andrew Cooper 5 months, 1 week ago
This is a tangle, but it's a small step in the right direction.

In the following change, xstate_init() is going to start using the Raw policy.

calculate_raw_cpu_policy() is sufficiently separate from the other policies to
safely move like this.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
---
CC: Jan Beulich <JBeulich@suse.com>
CC: Roger Pau Monné <roger.pau@citrix.com>
CC: Oleksii Kurochko <oleksii.kurochko@gmail.com>

This is necessary for the forthcoming xstate_{un,}compressed_size() to perform
boot-time sanity checks on state components which aren't fully enabled yet.  I
decided that doing this was better than extending the xstate_{offsets,sizes}[]
logic that we're intending to retire in due course.

v3:
 * New.
v4:
 * Adjust commit message a little.
---
 xen/arch/x86/cpu-policy.c | 1 -
 xen/arch/x86/setup.c      | 4 +++-
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/xen/arch/x86/cpu-policy.c b/xen/arch/x86/cpu-policy.c
index b96f4ee55cc4..5b66f002df05 100644
--- a/xen/arch/x86/cpu-policy.c
+++ b/xen/arch/x86/cpu-policy.c
@@ -845,7 +845,6 @@ static void __init calculate_hvm_def_policy(void)
 
 void __init init_guest_cpu_policies(void)
 {
-    calculate_raw_cpu_policy();
     calculate_host_policy();
 
     if ( IS_ENABLED(CONFIG_PV) )
diff --git a/xen/arch/x86/setup.c b/xen/arch/x86/setup.c
index dd51e68dbe5b..eee20bb1753c 100644
--- a/xen/arch/x86/setup.c
+++ b/xen/arch/x86/setup.c
@@ -1888,7 +1888,9 @@ void asmlinkage __init noreturn __start_xen(unsigned long mbi_p)
 
     tsx_init(); /* Needs microcode.  May change HLE/RTM feature bits. */
 
-    identify_cpu(&boot_cpu_data);
+    calculate_raw_cpu_policy(); /* Needs microcode.  No other dependenices. */
+
+    identify_cpu(&boot_cpu_data); /* Needs microcode and raw policy. */
 
     set_in_cr4(X86_CR4_OSFXSR | X86_CR4_OSXMMEXCPT);
 
-- 
2.39.2


Re: [PATCH v4 3/7] x86/boot: Collect the Raw CPU Policy earlier on boot
Posted by Jan Beulich 5 months ago
On 17.06.2024 19:39, Andrew Cooper wrote:
> This is a tangle, but it's a small step in the right direction.
> 
> In the following change, xstate_init() is going to start using the Raw policy.
> 
> calculate_raw_cpu_policy() is sufficiently separate from the other policies to
> safely move like this.
> 
> No functional change.
> 
> Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Reviewed-by: Jan Beulich <jbeulich@suse.com>