From fbf6449f84bf5e4ad09f2c09ee70ed7d629b5ff6 Mon Sep 17 00:00:00 2001 From: Adam Dunlap Date: Mon, 11 Sep 2023 17:27:03 -0700 Subject: [PATCH] x86/sev-es: Set x86_virt_bits to the correct value straight away, instead of a two-phase approach Instead of setting x86_virt_bits to a possibly-correct value and then correcting it later, do all the necessary checks before setting it. At this point, the #VC handler references boot_cpu_data.x86_virt_bits, and in the previous version, it would be triggered by the CPUIDs between the point at which it is set to 48 and when it is set to the correct value. Suggested-by: Dave Hansen Signed-off-by: Adam Dunlap Signed-off-by: Ingo Molnar Tested-by: Jacob Xu Link: https://lore.kernel.org/r/20230912002703.3924521-3-acdunlap@google.com --- arch/x86/kernel/cpu/common.c | 37 +++++++++++++++++++++--------------- 1 file changed, 22 insertions(+), 15 deletions(-) diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 382d4e6b848d..8d7063e4f63c 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -1114,17 +1114,32 @@ void get_cpu_cap(struct cpuinfo_x86 *c) void get_cpu_address_sizes(struct cpuinfo_x86 *c) { u32 eax, ebx, ecx, edx; + bool vp_bits_from_cpuid = true; - if (c->extended_cpuid_level >= 0x80000008) { + if (!cpu_has(c, X86_FEATURE_CPUID) || + (c->extended_cpuid_level < 0x80000008)) + vp_bits_from_cpuid = false; + + if (vp_bits_from_cpuid) { cpuid(0x80000008, &eax, &ebx, &ecx, &edx); c->x86_virt_bits = (eax >> 8) & 0xff; c->x86_phys_bits = eax & 0xff; + } else { + if (IS_ENABLED(CONFIG_X86_64)) { + c->x86_clflush_size = 64; + c->x86_phys_bits = 36; + c->x86_virt_bits = 48; + } else { + c->x86_clflush_size = 32; + c->x86_virt_bits = 32; + c->x86_phys_bits = 32; + + if (cpu_has(c, X86_FEATURE_PAE) || + cpu_has(c, X86_FEATURE_PSE36)) + c->x86_phys_bits = 36; + } } -#ifdef CONFIG_X86_32 - else if (cpu_has(c, X86_FEATURE_PAE) || cpu_has(c, X86_FEATURE_PSE36)) - c->x86_phys_bits = 36; -#endif c->x86_cache_bits = c->x86_phys_bits; } @@ -1579,15 +1594,6 @@ static void __init cpu_parse_early_param(void) */ static void __init early_identify_cpu(struct cpuinfo_x86 *c) { -#ifdef CONFIG_X86_64 - c->x86_clflush_size = 64; - c->x86_phys_bits = 36; - c->x86_virt_bits = 48; -#else - c->x86_clflush_size = 32; - c->x86_phys_bits = 32; - c->x86_virt_bits = 32; -#endif c->x86_cache_alignment = c->x86_clflush_size; memset(&c->x86_capability, 0, sizeof(c->x86_capability)); @@ -1601,7 +1607,6 @@ static void __init early_identify_cpu(struct cpuinfo_x86 *c) cpu_detect(c); get_cpu_vendor(c); get_cpu_cap(c); - get_cpu_address_sizes(c); setup_force_cpu_cap(X86_FEATURE_CPUID); cpu_parse_early_param(); @@ -1617,6 +1622,8 @@ static void __init early_identify_cpu(struct cpuinfo_x86 *c) setup_clear_cpu_cap(X86_FEATURE_CPUID); } + get_cpu_address_sizes(c); + setup_force_cpu_cap(X86_FEATURE_ALWAYS); cpu_set_bug_bits(c);