From c04fa5831d4d89dfbc88406f4a46f9846841a560 Mon Sep 17 00:00:00 2001 From: Alexey Kardashevskiy Date: Thu, 14 Aug 2014 15:03:07 +1000 Subject: PC, KVM, CMA: Fix regression caused by wrong get_order() use fc95ca7284bc54953165cba76c3228bd2cdb9591 claims that there is no functional change but this is not true as it calls get_order() (which takes bytes) where it should have called order_base_2() and the kernel stops on VM_BUG_ON(). This replaces get_order() with order_base_2() (round-up version of ilog2). Suggested-by: Paul Mackerras Cc: Alexander Graf Cc: Joonsoo Kim Cc: Benjamin Herrenschmidt Reviewed-by: Aneesh Kumar K.V Signed-off-by: Alexey Kardashevskiy Signed-off-by: Paolo Bonzini --- arch/powerpc/kvm/book3s_hv_builtin.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'arch') diff --git a/arch/powerpc/kvm/book3s_hv_builtin.c b/arch/powerpc/kvm/book3s_hv_builtin.c index 329d7fdd0a6a..b9615ba5b083 100644 --- a/arch/powerpc/kvm/book3s_hv_builtin.c +++ b/arch/powerpc/kvm/book3s_hv_builtin.c @@ -101,7 +101,7 @@ struct kvm_rma_info *kvm_alloc_rma() ri = kmalloc(sizeof(struct kvm_rma_info), GFP_KERNEL); if (!ri) return NULL; - page = cma_alloc(kvm_cma, kvm_rma_pages, get_order(kvm_rma_pages)); + page = cma_alloc(kvm_cma, kvm_rma_pages, order_base_2(kvm_rma_pages)); if (!page) goto err_out; atomic_set(&ri->use_count, 1); @@ -135,12 +135,12 @@ struct page *kvm_alloc_hpt(unsigned long nr_pages) { unsigned long align_pages = HPT_ALIGN_PAGES; - VM_BUG_ON(get_order(nr_pages) < KVM_CMA_CHUNK_ORDER - PAGE_SHIFT); + VM_BUG_ON(order_base_2(nr_pages) < KVM_CMA_CHUNK_ORDER - PAGE_SHIFT); /* Old CPUs require HPT aligned on a multiple of its size */ if (!cpu_has_feature(CPU_FTR_ARCH_206)) align_pages = nr_pages; - return cma_alloc(kvm_cma, nr_pages, get_order(align_pages)); + return cma_alloc(kvm_cma, nr_pages, order_base_2(align_pages)); } EXPORT_SYMBOL_GPL(kvm_alloc_hpt); -- cgit v1.2.3 From 3a6095a0173ad8f20c508446880558c9f9224324 Mon Sep 17 00:00:00 2001 From: Nadav Amit Date: Wed, 13 Aug 2014 16:50:13 +0300 Subject: KVM: x86: Avoid emulating instructions on #UD mistakenly Commit d40a6898e5 mistakenly caused instructions which are not marked as EmulateOnUD to be emulated upon #UD exception. The commit caused the check of whether the instruction flags include EmulateOnUD to never be evaluated. As a result instructions whose emulation is broken may be emulated. This fix moves the evaluation of EmulateOnUD so it would be evaluated. Signed-off-by: Nadav Amit [Tweak operand order in &&, remove EmulateOnUD where it's now superfluous. - Paolo] Signed-off-by: Paolo Bonzini --- arch/x86/kvm/emulate.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'arch') diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 56657b0bb3bb..ef117b842334 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -4394,8 +4394,11 @@ done_prefixes: ctxt->execute = opcode.u.execute; + if (unlikely(ctxt->ud) && likely(!(ctxt->d & EmulateOnUD))) + return EMULATION_FAILED; + if (unlikely(ctxt->d & - (NotImpl|EmulateOnUD|Stack|Op3264|Sse|Mmx|Intercept|CheckPerm))) { + (NotImpl|Stack|Op3264|Sse|Mmx|Intercept|CheckPerm))) { /* * These are copied unconditionally here, and checked unconditionally * in x86_emulate_insn. @@ -4406,9 +4409,6 @@ done_prefixes: if (ctxt->d & NotImpl) return EMULATION_FAILED; - if (!(ctxt->d & EmulateOnUD) && ctxt->ud) - return EMULATION_FAILED; - if (mode == X86EMUL_MODE_PROT64 && (ctxt->d & Stack)) ctxt->op_bytes = 8; -- cgit v1.2.3 From 9a4cfb27f7233610c5ddc82329c26d39683fad72 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Mon, 18 Aug 2014 13:15:51 +0200 Subject: KVM: x86: do not check CS.DPL against RPL during task switch This reverts the check added by commit 5045b468037d (KVM: x86: check CS.DPL against RPL during task switch, 2014-05-15). Although the CS.DPL=CS.RPL check is mentioned in table 7-1 of the SDM as causing a #TSS exception, it is not mentioned in table 6-6 that lists "invalid TSS conditions" which cause #TSS exceptions. In fact it causes some tests to fail, which pass on bare-metal. Keep the rest of the commit, since we will find new uses for it in 3.18. Reported-by: Nadav Amit Signed-off-by: Paolo Bonzini --- arch/x86/kvm/emulate.c | 3 --- 1 file changed, 3 deletions(-) (limited to 'arch') diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index ef117b842334..03954f7900f5 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -1491,9 +1491,6 @@ static int __load_segment_descriptor(struct x86_emulate_ctxt *ctxt, goto exception; break; case VCPU_SREG_CS: - if (in_task_switch && rpl != dpl) - goto exception; - if (!(seg_desc.type & 8)) goto exception; -- cgit v1.2.3 From 0d234daf7e0a3290a3a20c8087eefbd6335a5bd4 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Mon, 18 Aug 2014 16:39:48 +0200 Subject: Revert "KVM: x86: Increase the number of fixed MTRR regs to 10" This reverts commit 682367c494869008eb89ef733f196e99415ae862, which causes 32-bit SMP Windows 7 guests to panic. SeaBIOS has a limit on the number of MTRRs that it can handle, and this patch exceeded the limit. Better revert it. Thanks to Nadav Amit for debugging the cause. Cc: stable@nongnu.org Reported-by: Wanpeng Li Signed-off-by: Paolo Bonzini --- arch/x86/include/asm/kvm_host.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch') diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 572460175ba5..7c492ed9087b 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -95,7 +95,7 @@ static inline gfn_t gfn_to_index(gfn_t gfn, gfn_t base_gfn, int level) #define KVM_REFILL_PAGES 25 #define KVM_MAX_CPUID_ENTRIES 80 #define KVM_NR_FIXED_MTRR_REGION 88 -#define KVM_NR_VAR_MTRR 10 +#define KVM_NR_VAR_MTRR 8 #define ASYNC_PF_PER_VCPU 64 -- cgit v1.2.3