Commit fbf6449f authored by Adam Dunlap's avatar Adam Dunlap Committed by Ingo Molnar
Browse files

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: default avatarDave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: default avatarAdam Dunlap <acdunlap@google.com>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Tested-by: default avatarJacob Xu <jacobhxu@google.com>
Link: https://lore.kernel.org/r/20230912002703.3924521-3-acdunlap@google.com
parent f7993654

arch/x86/kernel/cpu/common.c

+22 −15
Original line number Diff line number Diff line
@@ -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;

	}

#ifdef CONFIG_X86_32

	else if (cpu_has(c, X86_FEATURE_PAE) || cpu_has(c, X86_FEATURE_PSE36))

	} else {

		if (IS_ENABLED(CONFIG_X86_64)) {

			c->x86_clflush_size = 64;

			c->x86_phys_bits = 36;

#endif

			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;

		}

	}

	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);