diff options
Diffstat (limited to 'arch/x86/lguest/boot.c')
| -rw-r--r-- | arch/x86/lguest/boot.c | 47 |
1 files changed, 33 insertions, 14 deletions
diff --git a/arch/x86/lguest/boot.c b/arch/x86/lguest/boot.c index db832fd65ecb..cf4603ba866f 100644 --- a/arch/x86/lguest/boot.c +++ b/arch/x86/lguest/boot.c @@ -56,6 +56,7 @@ #include <linux/lguest_launcher.h> #include <linux/virtio_console.h> #include <linux/pm.h> +#include <linux/export.h> #include <asm/apic.h> #include <asm/lguest.h> #include <asm/paravirt.h> @@ -70,8 +71,10 @@ #include <asm/i387.h> #include <asm/stackprotector.h> #include <asm/reboot.h> /* for struct machine_ops */ +#include <asm/kvm_para.h> -/*G:010 Welcome to the Guest! +/*G:010 + * Welcome to the Guest! * * The Guest in our tale is a simple creature: identical to the Host but * behaving in simplified but equivalent ways. In particular, the Guest is the @@ -190,15 +193,23 @@ static void lazy_hcall4(unsigned long call, #endif /*G:036 - * When lazy mode is turned off reset the per-cpu lazy mode variable and then - * issue the do-nothing hypercall to flush any stored calls. -:*/ + * When lazy mode is turned off, we issue the do-nothing hypercall to + * flush any stored calls, and call the generic helper to reset the + * per-cpu lazy mode variable. + */ static void lguest_leave_lazy_mmu_mode(void) { hcall(LHCALL_FLUSH_ASYNC, 0, 0, 0, 0); paravirt_leave_lazy_mmu(); } +/* + * We also catch the end of context switch; we enter lazy mode for much of + * that too, so again we need to flush here. + * + * (Technically, this is lazy CPU mode, and normally we're in lazy MMU + * mode, but unlike Xen, lguest doesn't care about the difference). + */ static void lguest_end_context_switch(struct task_struct *next) { hcall(LHCALL_FLUSH_ASYNC, 0, 0, 0, 0); @@ -391,7 +402,7 @@ static void lguest_load_tr_desc(void) * giant ball of hair. Its entry in the current Intel manual runs to 28 pages. * * This instruction even it has its own Wikipedia entry. The Wikipedia entry - * has been translated into 5 languages. I am not making this up! + * has been translated into 6 languages. I am not making this up! * * We could get funky here and identify ourselves as "GenuineLguest", but * instead we just use the real "cpuid" instruction. Then I pretty much turned @@ -446,6 +457,15 @@ static void lguest_cpuid(unsigned int *ax, unsigned int *bx, *ax &= 0xFFFFF0FF; *ax |= 0x00000500; break; + + /* + * This is used to detect if we're running under KVM. We might be, + * but that's a Host matter, not us. So say we're not. + */ + case KVM_CPUID_SIGNATURE: + *bx = *cx = *dx = 0; + break; + /* * 0x80000000 returns the highest Extended Function, so we futureproof * like we do above by limiting it to known fields. @@ -458,7 +478,7 @@ static void lguest_cpuid(unsigned int *ax, unsigned int *bx, /* * PAE systems can mark pages as non-executable. Linux calls this the * NX bit. Intel calls it XD (eXecute Disable), AMD EVP (Enhanced - * Virus Protection). We just switch turn if off here, since we don't + * Virus Protection). We just switch it off here, since we don't * support it. */ case 0x80000001: @@ -520,17 +540,16 @@ static unsigned long lguest_read_cr2(void) /* See lguest_set_pte() below. */ static bool cr3_changed = false; +static unsigned long current_cr3; /* * cr3 is the current toplevel pagetable page: the principle is the same as - * cr0. Keep a local copy, and tell the Host when it changes. The only - * difference is that our local copy is in lguest_data because the Host needs - * to set it upon our initial hypercall. + * cr0. Keep a local copy, and tell the Host when it changes. */ static void lguest_write_cr3(unsigned long cr3) { - lguest_data.pgdir = cr3; lazy_hcall1(LHCALL_NEW_PGTABLE, cr3); + current_cr3 = cr3; /* These two page tables are simple, linear, and used during boot */ if (cr3 != __pa(swapper_pg_dir) && cr3 != __pa(initial_page_table)) @@ -539,7 +558,7 @@ static void lguest_write_cr3(unsigned long cr3) static unsigned long lguest_read_cr3(void) { - return lguest_data.pgdir; + return current_cr3; } /* cr4 is used to enable and disable PGE, but we don't care. */ @@ -641,7 +660,7 @@ static void lguest_write_cr4(unsigned long val) /* * The Guest calls this after it has set a second-level entry (pte), ie. to map - * a page into a process' address space. Wetell the Host the toplevel and + * a page into a process' address space. We tell the Host the toplevel and * address this corresponds to. The Guest uses one pagetable per process, so * we need to tell the Host which one we're changing (mm->pgd). */ @@ -758,7 +777,7 @@ static void lguest_pmd_clear(pmd_t *pmdp) static void lguest_flush_tlb_single(unsigned long addr) { /* Simply set it to zero: if it was not, it will fault back in. */ - lazy_hcall3(LHCALL_SET_PTE, lguest_data.pgdir, addr, 0); + lazy_hcall3(LHCALL_SET_PTE, current_cr3, addr, 0); } /* @@ -1140,7 +1159,7 @@ static struct notifier_block paniced = { static __init char *lguest_memory_setup(void) { /* - *The Linux bootloader header contains an "e820" memory map: the + * The Linux bootloader header contains an "e820" memory map: the * Launcher populated the first entry with our memory limit. */ e820_add_region(boot_params.e820_map[0].addr, |