diff options
Diffstat (limited to 'arch/x86/xen/enlighten.c')
| -rw-r--r-- | arch/x86/xen/enlighten.c | 63 |
1 files changed, 55 insertions, 8 deletions
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index 0b95c9b8283f..30d12afe52ed 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -84,6 +84,7 @@ #include "mmu.h" #include "smp.h" #include "multicalls.h" +#include "pmu.h" EXPORT_SYMBOL_GPL(hypercall_page); @@ -483,6 +484,7 @@ static void set_aliased_prot(void *v, pgprot_t prot) pte_t pte; unsigned long pfn; struct page *page; + unsigned char dummy; ptep = lookup_address((unsigned long)v, &level); BUG_ON(ptep == NULL); @@ -492,6 +494,32 @@ static void set_aliased_prot(void *v, pgprot_t prot) pte = pfn_pte(pfn, prot); + /* + * Careful: update_va_mapping() will fail if the virtual address + * we're poking isn't populated in the page tables. We don't + * need to worry about the direct map (that's always in the page + * tables), but we need to be careful about vmap space. In + * particular, the top level page table can lazily propagate + * entries between processes, so if we've switched mms since we + * vmapped the target in the first place, we might not have the + * top-level page table entry populated. + * + * We disable preemption because we want the same mm active when + * we probe the target and when we issue the hypercall. We'll + * have the same nominal mm, but if we're a kernel thread, lazy + * mm dropping could change our pgd. + * + * Out of an abundance of caution, this uses __get_user() to fault + * in the target address just in case there's some obscure case + * in which the target address isn't readable. + */ + + preempt_disable(); + + pagefault_disable(); /* Avoid warnings due to being atomic. */ + __get_user(dummy, (unsigned char __user __force *)v); + pagefault_enable(); + if (HYPERVISOR_update_va_mapping((unsigned long)v, pte, 0)) BUG(); @@ -503,6 +531,8 @@ static void set_aliased_prot(void *v, pgprot_t prot) BUG(); } else kmap_flush_unused(); + + preempt_enable(); } static void xen_alloc_ldt(struct desc_struct *ldt, unsigned entries) @@ -510,6 +540,17 @@ static void xen_alloc_ldt(struct desc_struct *ldt, unsigned entries) const unsigned entries_per_page = PAGE_SIZE / LDT_ENTRY_SIZE; int i; + /* + * We need to mark the all aliases of the LDT pages RO. We + * don't need to call vm_flush_aliases(), though, since that's + * only responsible for flushing aliases out the TLBs, not the + * page tables, and Xen will flush the TLB for us if needed. + * + * To avoid confusing future readers: none of this is necessary + * to load the LDT. The hypervisor only checks this when the + * LDT is faulted in due to subsequent descriptor access. + */ + for(i = 0; i < entries; i += entries_per_page) set_aliased_prot(ldt + i, PAGE_KERNEL_RO); } @@ -970,8 +1011,7 @@ static void xen_write_cr0(unsigned long cr0) static void xen_write_cr4(unsigned long cr4) { - cr4 &= ~X86_CR4_PGE; - cr4 &= ~X86_CR4_PSE; + cr4 &= ~(X86_CR4_PGE | X86_CR4_PSE | X86_CR4_PCE); native_write_cr4(cr4); } @@ -990,6 +1030,9 @@ static u64 xen_read_msr_safe(unsigned int msr, int *err) { u64 val; + if (pmu_msr_read(msr, &val, err)) + return val; + val = native_read_msr_safe(msr, err); switch (msr) { case MSR_IA32_APICBASE: @@ -1036,7 +1079,8 @@ static int xen_write_msr_safe(unsigned int msr, unsigned low, unsigned high) Xen console noise. */ default: - ret = native_write_msr_safe(msr, low, high); + if (!pmu_msr_write(msr, low, high, &ret)) + ret = native_write_msr_safe(msr, low, high); } return ret; @@ -1175,10 +1219,7 @@ static const struct pv_cpu_ops xen_cpu_ops __initconst = { .read_msr = xen_read_msr_safe, .write_msr = xen_write_msr_safe, - .read_tsc = native_read_tsc, - .read_pmc = native_read_pmc, - - .read_tscp = native_read_tscp, + .read_pmc = xen_read_pmc, .iret = xen_iret, #ifdef CONFIG_X86_64 @@ -1227,6 +1268,10 @@ static const struct pv_apic_ops xen_apic_ops __initconst = { static void xen_reboot(int reason) { struct sched_shutdown r = { .reason = reason }; + int cpu; + + for_each_online_cpu(cpu) + xen_pmu_finish(cpu); if (HYPERVISOR_sched_op(SCHEDOP_shutdown, &r)) BUG(); @@ -1570,7 +1615,9 @@ asmlinkage __visible void __init xen_start_kernel(void) early_boot_irqs_disabled = true; xen_raw_console_write("mapping kernel into physical memory\n"); - xen_setup_kernel_pagetable((pgd_t *)xen_start_info->pt_base, xen_start_info->nr_pages); + xen_setup_kernel_pagetable((pgd_t *)xen_start_info->pt_base, + xen_start_info->nr_pages); + xen_reserve_special_pages(); /* * Modify the cache mode translation tables to match Xen's PAT |