[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-changelog] [IA64] tlb miss fix
# HG changeset patch # User awilliam@xxxxxxxxxxx # Node ID f94931b07c67327d5cd983cc10c37976f4bb6236 # Parent 5de0ee4ae76bcf70a08c063b5936fc6ffe2733b4 [IA64] tlb miss fix make dtlb miss handler to handle xen/ia64 identity mapping area. xen/ia64 enables vhpt walker for all regions unlink Linux. So dtlb misses on identity mapping area are catched by dtlb miss handler, not alt dltb miss handler. - dtlb miss on identity mapping area must be handled - alt dtlb miss must be handled - itlb miss on the identity mapping area must not occur panic via page_fault(). - alt itlb miss by a guest must be handled it occurs during dom0 boot. - alt itlb miss by xen must not occur panic by FORCE_CRASH vmx_ivt.S already has such tweaks by checking psr.vm bit. TODO: optimization dtlb miss handlers are performance critical so that it should be heavily optimized like alt_dtlb_miss. Signed-off-by: Isaku Yamahata <yamahata@xxxxxxxxxxxxx> diff -r 5de0ee4ae76b -r f94931b07c67 xen/arch/ia64/xen/ivt.S --- a/xen/arch/ia64/xen/ivt.S Fri Feb 24 15:29:52 2006 +++ b/xen/arch/ia64/xen/ivt.S Fri Feb 24 15:34:11 2006 @@ -298,12 +298,83 @@ DBG_FAULT(2) #ifdef XEN VHPT_CCHAIN_LOOKUP(dtlb_miss,d) +#if VHPT_ENABLED + // XXX TODO optimization + mov r31=pr // save predicates + mov r30=cr.ipsr + mov r28=cr.iip + mov r16=cr.ifa // get virtual address + mov r17=cr.isr // save predicates + ;; + + extr.u r18 = r30, IA64_PSR_CPL0_BIT, 2 // extract psr.cpl + ;; + cmp.ne p6, p0 = r0, r18 // cpl == 0? +(p6) br.cond.sptk 2f + + // is speculation bit on? + tbit.nz p7,p0=r17,IA64_ISR_SP_BIT + ;; +(p7) br.cond.spnt 2f + + // is non-access bit on? + tbit.nz p8,p0=r17,IA64_ISR_NA_BIT + ;; +(p8) br.cond.spnt 2f + + // cr.isr.code == IA64_ISR_CODE_LFETCH? + and r18=IA64_ISR_CODE_MASK,r17 // get the isr.code field + ;; + cmp.eq p9,p0=IA64_ISR_CODE_LFETCH,r18 // check isr.code field +(p9) br.cond.spnt 2f + + // Is the faulted iip in vmm area? + // check [59:58] bit + // 00, 11: guest + // 01, 10: vmm + extr.u r19 = r28, 58, 2 + ;; + cmp.eq p10, p0 = 0x0, r19 +(p10) br.cond.sptk 2f + cmp.eq p11, p0 = 0x3, r19 +(p11) br.cond.sptk 2f + + // Is the faulted address is in the identity mapping area? + // 0xf000... or 0xe8000... + extr.u r20 = r16, 59, 5 + ;; + cmp.eq p12, p0 = 0x1e, r20 // (0xf0 >> 3) = 0x1e +(p12) br.cond.spnt 1f + cmp.eq p0, p13 = 0x1d, r20 // (0xe8 >> 3) = 0x1d +(p13) br.cond.sptk 2f + +1: + // xen identity mappin area. + movl r24=PAGE_KERNEL + movl r25=(((1 << IA64_MAX_PHYS_BITS) - 1) & ~0xfff) + ;; + shr.u r26=r16,55 // move address bit 59 to bit 4 + and r25=r25,r16 // clear ed, reserved bits, and PTE control bits + ;; + and r26=0x10,r26 // bit 4=address-bit(59) + ;; + or r25=r25,r24 // insert PTE control bits into r25 + ;; + or r25=r25,r26 // set bit 4 (uncached) if the access was to region 6 + ;; + itc.d r25 // insert the TLB entry + mov pr=r31,-1 + rfi + +2: +#endif #ifdef VHPT_GLOBAL // br.cond.sptk page_fault br.cond.sptk fast_tlb_miss_reflect ;; #endif -#endif + mov r29=b0 // save b0 +#else /* * The DTLB handler accesses the L3 PTE via the virtually mapped linear * page table. If a nested TLB miss occurs, we switch into physical @@ -313,6 +384,7 @@ mov r16=cr.ifa // get virtual address mov r29=b0 // save b0 mov r31=pr // save predicates +#endif dtlb_fault: mov r17=cr.iha // get virtual address of L3 PTE movl r30=1f // load nested fault continuation point @@ -399,6 +471,9 @@ ;; or r19=r19,r18 // set bit 4 (uncached) if the access was to region 6 (p8) br.cond.spnt page_fault +#ifdef XEN + FORCE_CRASH +#endif ;; itc.i r19 // insert the TLB entry mov pr=r31,-1 diff -r 5de0ee4ae76b -r f94931b07c67 xen/include/asm-ia64/config.h --- a/xen/include/asm-ia64/config.h Fri Feb 24 15:29:52 2006 +++ b/xen/include/asm-ia64/config.h Fri Feb 24 15:34:11 2006 @@ -251,8 +251,6 @@ #define seq_printf(a,b...) printf(b) #define CONFIG_BLK_DEV_INITRD // needed to reserve memory for domain0 -#define FORCE_CRASH() asm("break 0;;"); - void dummy_called(char *function); #define dummy() dummy_called(__FUNCTION__) @@ -301,6 +299,9 @@ #ifndef __ASSEMBLY__ #include <linux/linkage.h> +#define FORCE_CRASH() asm("break.m 0;;"); +#else +#define FORCE_CRASH break.m 0;; #endif #endif /* _IA64_CONFIG_H_ */ _______________________________________________ Xen-changelog mailing list Xen-changelog@xxxxxxxxxxxxxxxxxxx http://lists.xensource.com/xen-changelog
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