The following commit has been merged into the x86/urgent branch of tip:
Commit-ID: 9a458198eba98b7207669a166e64d04b04cb651b Gitweb: https://git.kernel.org/tip/9a458198eba98b7207669a166e64d04b04cb651b Author: Paolo Bonzini pbonzini@redhat.com AuthorDate: Thu, 01 Feb 2024 00:09:01 +01:00 Committer: Dave Hansen dave.hansen@linux.intel.com CommitterDate: Mon, 26 Feb 2024 08:16:15 -08:00
x86/cpu: Allow reducing x86_phys_bits during early_identify_cpu()
In commit fbf6449f84bf ("x86/sev-es: Set x86_virt_bits to the correct value straight away, instead of a two-phase approach"), the initialization of c->x86_phys_bits was moved after this_cpu->c_early_init(c). This is incorrect because early_init_amd() expected to be able to reduce the value according to the contents of CPUID leaf 0x8000001f.
Fortunately, the bug was negated by init_amd()'s call to early_init_amd(), which does reduce x86_phys_bits in the end. However, this is very late in the boot process and, most notably, the wrong value is used for x86_phys_bits when setting up MTRRs.
To fix this, call get_cpu_address_sizes() as soon as X86_FEATURE_CPUID is set/cleared, and c->extended_cpuid_level is retrieved.
Fixes: fbf6449f84bf ("x86/sev-es: Set x86_virt_bits to the correct value straight away, instead of a two-phase approach") Signed-off-by: Paolo Bonzini pbonzini@redhat.com Signed-off-by: Dave Hansen dave.hansen@linux.intel.com Cc:stable@vger.kernel.org Link: https://lore.kernel.org/all/20240131230902.1867092-2-pbonzini%40redhat.com --- arch/x86/kernel/cpu/common.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 0b97bcd..fbc4e60 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -1589,6 +1589,7 @@ static void __init early_identify_cpu(struct cpuinfo_x86 *c) get_cpu_vendor(c); get_cpu_cap(c); setup_force_cpu_cap(X86_FEATURE_CPUID); + get_cpu_address_sizes(c); cpu_parse_early_param();
if (this_cpu->c_early_init) @@ -1601,10 +1602,9 @@ static void __init early_identify_cpu(struct cpuinfo_x86 *c) this_cpu->c_bsp_init(c); } else { setup_clear_cpu_cap(X86_FEATURE_CPUID); + get_cpu_address_sizes(c); }
- get_cpu_address_sizes(c); - setup_force_cpu_cap(X86_FEATURE_ALWAYS);
cpu_set_bug_bits(c);