On systems that do not have hardware enforced cache coherency between encrypted and unencrypted mappings of the same physical page, the hypervisor can use the VM page flush MSR (0xc001011e) to flush the cache contents of an SEV guest page. When a small number of pages are being flushed, this can be used in place of issuing a WBINVD across all CPUs. CPUID 0x8000001f_eax[2] is used to determine if the VM page flush MSR is available. Add a CPUID feature to indicate it is supported and define the MSR. Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Message-Id: <f1966379e31f9b208db5257509c4a089a87d33d0.1607620209.git.thomas.lendacky@amd.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
73 lines
2.3 KiB
C
73 lines
2.3 KiB
C
/*
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* Routines to identify additional cpu features that are scattered in
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* cpuid space.
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*/
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#include <linux/cpu.h>
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#include <asm/memtype.h>
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#include <asm/apic.h>
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#include <asm/processor.h>
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#include "cpu.h"
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struct cpuid_bit {
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u16 feature;
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u8 reg;
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u8 bit;
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u32 level;
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u32 sub_leaf;
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};
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/*
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* Please keep the leaf sorted by cpuid_bit.level for faster search.
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* X86_FEATURE_MBA is supported by both Intel and AMD. But the CPUID
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* levels are different and there is a separate entry for each.
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*/
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static const struct cpuid_bit cpuid_bits[] = {
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{ X86_FEATURE_APERFMPERF, CPUID_ECX, 0, 0x00000006, 0 },
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{ X86_FEATURE_EPB, CPUID_ECX, 3, 0x00000006, 0 },
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{ X86_FEATURE_CQM_LLC, CPUID_EDX, 1, 0x0000000f, 0 },
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{ X86_FEATURE_CQM_OCCUP_LLC, CPUID_EDX, 0, 0x0000000f, 1 },
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{ X86_FEATURE_CQM_MBM_TOTAL, CPUID_EDX, 1, 0x0000000f, 1 },
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{ X86_FEATURE_CQM_MBM_LOCAL, CPUID_EDX, 2, 0x0000000f, 1 },
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{ X86_FEATURE_CAT_L3, CPUID_EBX, 1, 0x00000010, 0 },
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{ X86_FEATURE_CAT_L2, CPUID_EBX, 2, 0x00000010, 0 },
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{ X86_FEATURE_CDP_L3, CPUID_ECX, 2, 0x00000010, 1 },
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{ X86_FEATURE_CDP_L2, CPUID_ECX, 2, 0x00000010, 2 },
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{ X86_FEATURE_MBA, CPUID_EBX, 3, 0x00000010, 0 },
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{ X86_FEATURE_PER_THREAD_MBA, CPUID_ECX, 0, 0x00000010, 3 },
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{ X86_FEATURE_HW_PSTATE, CPUID_EDX, 7, 0x80000007, 0 },
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{ X86_FEATURE_CPB, CPUID_EDX, 9, 0x80000007, 0 },
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{ X86_FEATURE_PROC_FEEDBACK, CPUID_EDX, 11, 0x80000007, 0 },
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{ X86_FEATURE_MBA, CPUID_EBX, 6, 0x80000008, 0 },
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{ X86_FEATURE_SME, CPUID_EAX, 0, 0x8000001f, 0 },
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{ X86_FEATURE_SEV, CPUID_EAX, 1, 0x8000001f, 0 },
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{ X86_FEATURE_SEV_ES, CPUID_EAX, 3, 0x8000001f, 0 },
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{ X86_FEATURE_SME_COHERENT, CPUID_EAX, 10, 0x8000001f, 0 },
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{ X86_FEATURE_VM_PAGE_FLUSH, CPUID_EAX, 2, 0x8000001f, 0 },
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{ 0, 0, 0, 0, 0 }
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};
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void init_scattered_cpuid_features(struct cpuinfo_x86 *c)
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{
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u32 max_level;
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u32 regs[4];
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const struct cpuid_bit *cb;
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for (cb = cpuid_bits; cb->feature; cb++) {
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/* Verify that the level is valid */
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max_level = cpuid_eax(cb->level & 0xffff0000);
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if (max_level < cb->level ||
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max_level > (cb->level | 0xffff))
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continue;
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cpuid_count(cb->level, cb->sub_leaf, ®s[CPUID_EAX],
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®s[CPUID_EBX], ®s[CPUID_ECX],
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®s[CPUID_EDX]);
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if (regs[cb->reg] & (1 << cb->bit))
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set_cpu_cap(c, cb->feature);
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}
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}
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