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Tweak the logic to disable CLFLUSH in virtual environments to work around

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problems with flushing the local APIC register range so that it checks
vm_guest directly.

Reviewed by:	kib, alc
MFC after:	2 weeks
This commit is contained in:
jhb 2010-08-02 17:01:23 +00:00
parent ec28b7bf63
commit c6eb2c5ec7
2 changed files with 12 additions and 12 deletions
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12
sys/amd64/amd64/initcpu.c
View File

@ -177,17 +177,17 @@ initializecpucache()
if ((cpu_feature & CPUID_CLFSH) != 0)
cpu_clflush_line_size = ((cpu_procinfo >> 8) & 0xff) * 8;
/*
* XXXKIB: (temporary) hack to work around traps generated when
* CLFLUSHing APIC registers window.
* XXXKIB: (temporary) hack to work around traps generated
* when CLFLUSHing APIC register window under virtualization
* environments. These environments tend to disable the
* CPUID_SS feature even though the native CPU supports it.
*/
TUNABLE_INT_FETCH("hw.clflush_disable", &hw_clflush_disable);
if (cpu_vendor_id == CPU_VENDOR_INTEL && !(cpu_feature & CPUID_SS) &&
hw_clflush_disable == -1)
if (vm_guest != VM_GUEST_NO && hw_clflush_disable == -1)
cpu_feature &= ~CPUID_CLFSH;
/*
* Allow to disable CLFLUSH feature manually by
* hw.clflush_disable tunable. This may help Xen guest on some AMD
* CPUs.
* hw.clflush_disable tunable.
*/
if (hw_clflush_disable == 1)
cpu_feature &= ~CPUID_CLFSH;

12
sys/i386/i386/initcpu.c
View File

@ -724,17 +724,17 @@ initializecpu(void)
if ((cpu_feature & CPUID_CLFSH) != 0)
cpu_clflush_line_size = ((cpu_procinfo >> 8) & 0xff) * 8;
/*
* XXXKIB: (temporary) hack to work around traps generated when
* CLFLUSHing APIC registers window.
* XXXKIB: (temporary) hack to work around traps generated
* when CLFLUSHing APIC register window under virtualization
* environments. These environments tend to disable the
* CPUID_SS feature even though the native CPU supports it.
*/
TUNABLE_INT_FETCH("hw.clflush_disable", &hw_clflush_disable);
if (cpu_vendor_id == CPU_VENDOR_INTEL && !(cpu_feature & CPUID_SS) &&
hw_clflush_disable == -1)
if (vm_guest != VM_GUEST_NO && hw_clflush_disable == -1)
cpu_feature &= ~CPUID_CLFSH;
/*
* Allow to disable CLFLUSH feature manually by
* hw.clflush_disable tunable. This may help Xen guest on some AMD
* CPUs.
* hw.clflush_disable tunable.
*/
if (hw_clflush_disable == 1)
cpu_feature &= ~CPUID_CLFSH;