Now that the feature is officially documented (see http://support.amd.com/us/Processor_TechDocs/24593.pdf), I think it makes sense to also allow HVM guests to make use of it. Signed-off-by: Jan Beulich <jbeulich@novell.com> Cc: Andre Przywara <andre.przywara@amd.com> --- 2010-05-04.orig/xen/arch/x86/hvm/hvm.c 2010-04-22 14:43:25.000000000 +0200 +++ 2010-05-04/xen/arch/x86/hvm/hvm.c 2010-05-04 13:26:07.000000000 +0200 @@ -590,6 +590,7 @@ static bool_t hvm_efer_valid(uint64_t va ((sizeof(long) != 8) && (value & EFER_LME)) || (!cpu_has_nx && (value & EFER_NX)) || (!cpu_has_syscall && (value & EFER_SCE)) || + (!cpu_has_lmsl && (value & EFER_LMSLE)) || (!cpu_has_ffxsr && (value & EFER_FFXSE)) || ((value & (EFER_LME|EFER_LMA)) == EFER_LMA)); } @@ -641,7 +642,8 @@ static int hvm_load_cpu_ctxt(struct doma } if ( !hvm_efer_valid( - ctxt.msr_efer, EFER_FFXSE | EFER_LME | EFER_LMA | EFER_NX | EFER_SCE) ) + ctxt.msr_efer, + EFER_FFXSE | EFER_LMSLE | EFER_LME | EFER_LMA | EFER_NX | EFER_SCE) ) { gdprintk(XENLOG_ERR, "HVM restore: bad EFER 0x%"PRIx64"\n", ctxt.msr_efer); @@ -995,7 +997,8 @@ int hvm_set_efer(uint64_t value) value &= ~EFER_LMA; - if ( !hvm_efer_valid(value, EFER_FFXSE | EFER_LME | EFER_NX | EFER_SCE) ) + if ( !hvm_efer_valid(value, + EFER_FFXSE | EFER_LMSLE | EFER_LME | EFER_NX | EFER_SCE) ) { gdprintk(XENLOG_WARNING, "Trying to set reserved bit in " "EFER: %"PRIx64"\n", value); --- 2010-05-04.orig/xen/arch/x86/hvm/svm/svm.c 2010-04-12 11:28:20.000000000 +0200 +++ 2010-05-04/xen/arch/x86/hvm/svm/svm.c 2010-05-04 13:23:02.000000000 +0200 @@ -57,6 +57,11 @@ u32 svm_feature_flags; +#ifdef __x86_64__ +/* indicate whether guest may use EFER.LMSLE */ +unsigned char cpu_has_lmsl = 0; +#endif + #define set_segment_register(name, value) \ asm volatile ( "movw %%ax ,%%" STR(name) "" : : "a" (value) ) @@ -848,6 +853,29 @@ static int svm_cpu_up(struct cpuinfo_x86 /* Initialize core''s ASID handling. */ svm_asid_init(c); +#ifdef __x86_64__ + /* + * Check whether EFER.LMSLE can be written. + * Unfortunately there''s no feature bit defined for this. + */ + eax = read_efer(); + edx = read_efer() >> 32; + if ( wrmsr_safe(MSR_EFER, eax | EFER_LMSLE, edx) == 0 ) + rdmsr(MSR_EFER, eax, edx); + if ( eax & EFER_LMSLE ) + { + if ( c == &boot_cpu_data ) + cpu_has_lmsl = 1; + wrmsr(MSR_EFER, eax ^ EFER_LMSLE, edx); + } + else + { + if ( cpu_has_lmsl ) + printk(XENLOG_WARNING "Inconsistent LMLSE support across CPUs!\n"); + cpu_has_lmsl = 0; + } +#endif + return 1; } --- 2010-05-04.orig/xen/include/asm-x86/hvm/hvm.h 2010-04-12 11:28:20.000000000 +0200 +++ 2010-05-04/xen/include/asm-x86/hvm/hvm.h 2010-05-04 13:23:02.000000000 +0200 @@ -136,6 +136,12 @@ struct hvm_function_table { extern struct hvm_function_table hvm_funcs; extern int hvm_enabled; +#ifdef __i386__ +# define cpu_has_lmsl 0 +#else +extern unsigned char cpu_has_lmsl; +#endif + int hvm_domain_initialise(struct domain *d); void hvm_domain_relinquish_resources(struct domain *d); void hvm_domain_destroy(struct domain *d); _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel