[PATCH] i386: vMI backend for paravirt-ops

Fairly straightforward implementation of VMI backend for paravirt-ops.

[Adrian Bunk: some cleanups]

Signed-off-by: Zachary Amsden <zach@vmware.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>

1 files changed, 904 insertions, 0 deletions

diff --git a/arch/i386/kernel/vmi.c b/arch/i386/kernel/vmi.c
new file mode 100644
index 000000000000..a94d64b10f75
--- /dev/null
+++ b/arch/i386/kernel/vmi.c
@@ -0,0 +1,904 @@
+/*
+ * VMI specific paravirt-ops implementation
+ *
+ * Copyright (C) 2005, VMware, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ * NON INFRINGEMENT.  See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ * Send feedback to zach@vmware.com
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/license.h>
+#include <linux/cpu.h>
+#include <linux/bootmem.h>
+#include <linux/mm.h>
+#include <asm/vmi.h>
+#include <asm/io.h>
+#include <asm/fixmap.h>
+#include <asm/apicdef.h>
+#include <asm/apic.h>
+#include <asm/processor.h>
+#include <asm/timer.h>
+
+/* Convenient for calling VMI functions indirectly in the ROM */
+typedef u32 __attribute__((regparm(1))) (VROMFUNC)(void);
+typedef u64 __attribute__((regparm(2))) (VROMLONGFUNC)(int);
+
+#define call_vrom_func(rom,func) \
+   (((VROMFUNC *)(rom->func))())
+
+#define call_vrom_long_func(rom,func,arg) \
+   (((VROMLONGFUNC *)(rom->func)) (arg))
+
+static struct vrom_header *vmi_rom;
+static int license_gplok;
+static int disable_nodelay;
+static int disable_pge;
+static int disable_pse;
+static int disable_sep;
+static int disable_tsc;
+static int disable_mtrr;
+
+/* Cached VMI operations */
+struct {
+        void (*cpuid)(void /* non-c */);
+        void (*_set_ldt)(u32 selector);
+        void (*set_tr)(u32 selector);
+        void (*set_kernel_stack)(u32 selector, u32 esp0);
+        void (*allocate_page)(u32, u32, u32, u32, u32);
+        void (*release_page)(u32, u32);
+        void (*set_pte)(pte_t, pte_t *, unsigned);
+        void (*update_pte)(pte_t *, unsigned);
+        void (*set_linear_mapping)(int, u32, u32, u32);
+        void (*flush_tlb)(int);
+        void (*set_initial_ap_state)(int, int);
+} vmi_ops;
+
+/* XXX move this to alternative.h */
+extern struct paravirt_patch __start_parainstructions[],
+        __stop_parainstructions[];
+
+/*
+ * VMI patching routines.
+ */
+#define MNEM_CALL 0xe8
+#define MNEM_JMP  0xe9
+#define MNEM_RET  0xc3
+
+static char irq_save_disable_callout[] = {
+        MNEM_CALL, 0, 0, 0, 0,
+        MNEM_CALL, 0, 0, 0, 0,
+        MNEM_RET
+};
+#define IRQ_PATCH_INT_MASK 0
+#define IRQ_PATCH_DISABLE  5
+
+static inline void patch_offset(unsigned char *eip, unsigned char *dest)
+{
+        *(unsigned long *)(eip+1) = dest-eip-5;
+}
+
+static unsigned patch_internal(int call, unsigned len, void *insns)
+{
+        u64 reloc;
+        struct vmi_relocation_info *const rel = (struct vmi_relocation_info *)&reloc;
+        reloc = call_vrom_long_func(vmi_rom, get_reloc, call);
+        switch(rel->type) {
+                case VMI_RELOCATION_CALL_REL:
+                        BUG_ON(len < 5);
+                        *(char *)insns = MNEM_CALL;
+                        patch_offset(insns, rel->eip);
+                        return 5;
+
+                case VMI_RELOCATION_JUMP_REL:
+                        BUG_ON(len < 5);
+                        *(char *)insns = MNEM_JMP;
+                        patch_offset(insns, rel->eip);
+                        return 5;
+
+                case VMI_RELOCATION_NOP:
+                        /* obliterate the whole thing */
+                        return 0;
+
+                case VMI_RELOCATION_NONE:
+                        /* leave native code in place */
+                        break;
+
+                default:
+                        BUG();
+        }
+        return len;
+}
+
+/*
+ * Apply patch if appropriate, return length of new instruction
+ * sequence.  The callee does nop padding for us.
+ */
+static unsigned vmi_patch(u8 type, u16 clobbers, void *insns, unsigned len)
+{
+        switch (type) {
+                case PARAVIRT_IRQ_DISABLE:
+                        return patch_internal(VMI_CALL_DisableInterrupts, len, insns);
+                case PARAVIRT_IRQ_ENABLE:
+                        return patch_internal(VMI_CALL_EnableInterrupts, len, insns);
+                case PARAVIRT_RESTORE_FLAGS:
+                        return patch_internal(VMI_CALL_SetInterruptMask, len, insns);
+                case PARAVIRT_SAVE_FLAGS:
+                        return patch_internal(VMI_CALL_GetInterruptMask, len, insns);
+                case PARAVIRT_SAVE_FLAGS_IRQ_DISABLE:
+                        if (len >= 10) {
+                                patch_internal(VMI_CALL_GetInterruptMask, len, insns);
+                                patch_internal(VMI_CALL_DisableInterrupts, len-5, insns+5);
+                                return 10;
+                        } else {
+                                /*
+                                 * You bastards didn't leave enough room to
+                                 * patch save_flags_irq_disable inline.  Patch
+                                 * to a helper
+                                 */
+                                BUG_ON(len < 5);
+                                *(char *)insns = MNEM_CALL;
+                                patch_offset(insns, irq_save_disable_callout);
+                                return 5;
+                        }
+                case PARAVIRT_INTERRUPT_RETURN:
+                        return patch_internal(VMI_CALL_IRET, len, insns);
+                case PARAVIRT_STI_SYSEXIT:
+                        return patch_internal(VMI_CALL_SYSEXIT, len, insns);
+                default:
+                        break;
+        }
+        return len;
+}
+
+/* CPUID has non-C semantics, and paravirt-ops API doesn't match hardware ISA */
+static void vmi_cpuid(unsigned int *eax, unsigned int *ebx,
+                               unsigned int *ecx, unsigned int *edx)
+{
+        int override = 0;
+        if (*eax == 1)
+                override = 1;
+        asm volatile ("call *%6"
+                      : "=a" (*eax),
+                        "=b" (*ebx),
+                        "=c" (*ecx),
+                        "=d" (*edx)
+                      : "0" (*eax), "2" (*ecx), "r" (vmi_ops.cpuid));
+        if (override) {
+                if (disable_pse)
+                        *edx &= ~X86_FEATURE_PSE;
+                if (disable_pge)
+                        *edx &= ~X86_FEATURE_PGE;
+                if (disable_sep)
+                        *edx &= ~X86_FEATURE_SEP;
+                if (disable_tsc)
+                        *edx &= ~X86_FEATURE_TSC;
+                if (disable_mtrr)
+                        *edx &= ~X86_FEATURE_MTRR;
+        }
+}
+
+static inline void vmi_maybe_load_tls(struct desc_struct *gdt, int nr, struct desc_struct *new)
+{
+        if (gdt[nr].a != new->a || gdt[nr].b != new->b)
+                write_gdt_entry(gdt, nr, new->a, new->b);
+}
+
+static void vmi_load_tls(struct thread_struct *t, unsigned int cpu)
+{
+        struct desc_struct *gdt = get_cpu_gdt_table(cpu);
+        vmi_maybe_load_tls(gdt, GDT_ENTRY_TLS_MIN + 0, &t->tls_array[0]);
+        vmi_maybe_load_tls(gdt, GDT_ENTRY_TLS_MIN + 1, &t->tls_array[1]);
+        vmi_maybe_load_tls(gdt, GDT_ENTRY_TLS_MIN + 2, &t->tls_array[2]);
+}
+
+static void vmi_set_ldt(const void *addr, unsigned entries)
+{
+        unsigned cpu = smp_processor_id();
+        u32 low, high;
+
+        pack_descriptor(&low, &high, (unsigned long)addr,
+                        entries * sizeof(struct desc_struct) - 1,
+                        DESCTYPE_LDT, 0);
+        write_gdt_entry(get_cpu_gdt_table(cpu), GDT_ENTRY_LDT, low, high);
+        vmi_ops._set_ldt(entries ? GDT_ENTRY_LDT*sizeof(struct desc_struct) : 0);
+}
+
+static void vmi_set_tr(void)
+{
+        vmi_ops.set_tr(GDT_ENTRY_TSS*sizeof(struct desc_struct));
+}
+
+static void vmi_load_esp0(struct tss_struct *tss,
+                                   struct thread_struct *thread)
+{
+        tss->esp0 = thread->esp0;
+
+        /* This can only happen when SEP is enabled, no need to test "SEP"arately */
+        if (unlikely(tss->ss1 != thread->sysenter_cs)) {
+                tss->ss1 = thread->sysenter_cs;
+                wrmsr(MSR_IA32_SYSENTER_CS, thread->sysenter_cs, 0);
+        }
+        vmi_ops.set_kernel_stack(__KERNEL_DS, tss->esp0);
+}
+
+static void vmi_flush_tlb_user(void)
+{
+        vmi_ops.flush_tlb(VMI_FLUSH_TLB);
+}
+
+static void vmi_flush_tlb_kernel(void)
+{
+        vmi_ops.flush_tlb(VMI_FLUSH_TLB | VMI_FLUSH_GLOBAL);
+}
+
+/* Stub to do nothing at all; used for delays and unimplemented calls */
+static void vmi_nop(void)
+{
+}
+
+
+#ifdef CONFIG_DEBUG_PAGE_TYPE
+
+#ifdef CONFIG_X86_PAE
+#define MAX_BOOT_PTS (2048+4+1)
+#else
+#define MAX_BOOT_PTS (1024+1)
+#endif
+
+/*
+ * During boot, mem_map is not yet available in paging_init, so stash
+ * all the boot page allocations here.
+ */
+static struct {
+        u32 pfn;
+        int type;
+} boot_page_allocations[MAX_BOOT_PTS];
+static int num_boot_page_allocations;
+static int boot_allocations_applied;
+
+void vmi_apply_boot_page_allocations(void)
+{
+        int i;
+        BUG_ON(!mem_map);
+        for (i = 0; i < num_boot_page_allocations; i++) {
+                struct page *page = pfn_to_page(boot_page_allocations[i].pfn);
+                page->type = boot_page_allocations[i].type;
+                page->type = boot_page_allocations[i].type &
+                                ~(VMI_PAGE_ZEROED | VMI_PAGE_CLONE);
+        }
+        boot_allocations_applied = 1;
+}
+
+static void record_page_type(u32 pfn, int type)
+{
+        BUG_ON(num_boot_page_allocations >= MAX_BOOT_PTS);
+        boot_page_allocations[num_boot_page_allocations].pfn = pfn;
+        boot_page_allocations[num_boot_page_allocations].type = type;
+        num_boot_page_allocations++;
+}
+
+static void check_zeroed_page(u32 pfn, int type, struct page *page)
+{
+        u32 *ptr;
+        int i;
+        int limit = PAGE_SIZE / sizeof(int);
+
+        if (page_address(page))
+                ptr = (u32 *)page_address(page);
+        else
+                ptr = (u32 *)__va(pfn << PAGE_SHIFT);
+        /*
+         * When cloning the root in non-PAE mode, only the userspace
+         * pdes need to be zeroed.
+         */
+        if (type & VMI_PAGE_CLONE)
+                limit = USER_PTRS_PER_PGD;
+        for (i = 0; i < limit; i++)
+                BUG_ON(ptr[i]);
+}
+
+/*
+ * We stash the page type into struct page so we can verify the page
+ * types are used properly.
+ */
+static void vmi_set_page_type(u32 pfn, int type)
+{
+        /* PAE can have multiple roots per page - don't track */
+        if (PTRS_PER_PMD > 1 && (type & VMI_PAGE_PDP))
+                return;
+
+        if (boot_allocations_applied) {
+                struct page *page = pfn_to_page(pfn);
+                if (type != VMI_PAGE_NORMAL)
+                        BUG_ON(page->type);
+                else
+                        BUG_ON(page->type == VMI_PAGE_NORMAL);
+                page->type = type & ~(VMI_PAGE_ZEROED | VMI_PAGE_CLONE);
+                if (type & VMI_PAGE_ZEROED)
+                        check_zeroed_page(pfn, type, page);
+        } else {
+                record_page_type(pfn, type);
+        }
+}
+
+static void vmi_check_page_type(u32 pfn, int type)
+{
+        /* PAE can have multiple roots per page - skip checks */
+        if (PTRS_PER_PMD > 1 && (type & VMI_PAGE_PDP))
+                return;
+
+        type &= ~(VMI_PAGE_ZEROED | VMI_PAGE_CLONE);
+        if (boot_allocations_applied) {
+                struct page *page = pfn_to_page(pfn);
+                BUG_ON((page->type ^ type) & VMI_PAGE_PAE);
+                BUG_ON(type == VMI_PAGE_NORMAL && page->type);
+                BUG_ON((type & page->type) == 0);
+        }
+}
+#else
+#define vmi_set_page_type(p,t) do { } while (0)
+#define vmi_check_page_type(p,t) do { } while (0)
+#endif
+
+static void vmi_allocate_pt(u32 pfn)
+{
+        vmi_set_page_type(pfn, VMI_PAGE_L1);
+        vmi_ops.allocate_page(pfn, VMI_PAGE_L1, 0, 0, 0);
+}
+
+static void vmi_allocate_pd(u32 pfn)
+{
+        /*
+         * This call comes in very early, before mem_map is setup.
+         * It is called only for swapper_pg_dir, which already has
+         * data on it.
+         */
+        vmi_set_page_type(pfn, VMI_PAGE_L2);
+        vmi_ops.allocate_page(pfn, VMI_PAGE_L2, 0, 0, 0);
+}
+
+static void vmi_allocate_pd_clone(u32 pfn, u32 clonepfn, u32 start, u32 count)
+{
+        vmi_set_page_type(pfn, VMI_PAGE_L2 | VMI_PAGE_CLONE);
+        vmi_check_page_type(clonepfn, VMI_PAGE_L2);
+        vmi_ops.allocate_page(pfn, VMI_PAGE_L2 | VMI_PAGE_CLONE, clonepfn, start, count);
+}
+
+static void vmi_release_pt(u32 pfn)
+{
+        vmi_ops.release_page(pfn, VMI_PAGE_L1);
+        vmi_set_page_type(pfn, VMI_PAGE_NORMAL);
+}
+
+static void vmi_release_pd(u32 pfn)
+{
+        vmi_ops.release_page(pfn, VMI_PAGE_L2);
+        vmi_set_page_type(pfn, VMI_PAGE_NORMAL);
+}
+
+/*
+ * Helper macros for MMU update flags.  We can defer updates until a flush
+ * or page invalidation only if the update is to the current address space
+ * (otherwise, there is no flush).  We must check against init_mm, since
+ * this could be a kernel update, which usually passes init_mm, although
+ * sometimes this check can be skipped if we know the particular function
+ * is only called on user mode PTEs.  We could change the kernel to pass
+ * current->active_mm here, but in particular, I was unsure if changing
+ * mm/highmem.c to do this would still be correct on other architectures.
+ */
+#define is_current_as(mm, mustbeuser) ((mm) == current->active_mm ||    \
+                                       (!mustbeuser && (mm) == &init_mm))
+#define vmi_flags_addr(mm, addr, level, user)                           \
+        ((level) | (is_current_as(mm, user) ?                           \
+                (VMI_PAGE_CURRENT_AS | ((addr) & VMI_PAGE_VA_MASK)) : 0))
+#define vmi_flags_addr_defer(mm, addr, level, user)                     \
+        ((level) | (is_current_as(mm, user) ?                           \
+                (VMI_PAGE_DEFER | VMI_PAGE_CURRENT_AS | ((addr) & VMI_PAGE_VA_MASK)) : 0))
+
+static void vmi_update_pte(struct mm_struct *mm, u32 addr, pte_t *ptep)
+{
+        vmi_check_page_type(__pa(ptep) >> PAGE_SHIFT, VMI_PAGE_PTE);
+        vmi_ops.update_pte(ptep, vmi_flags_addr(mm, addr, VMI_PAGE_PT, 0));
+}
+
+static void vmi_update_pte_defer(struct mm_struct *mm, u32 addr, pte_t *ptep)
+{
+        vmi_check_page_type(__pa(ptep) >> PAGE_SHIFT, VMI_PAGE_PTE);
+        vmi_ops.update_pte(ptep, vmi_flags_addr_defer(mm, addr, VMI_PAGE_PT, 0));
+}
+
+static void vmi_set_pte(pte_t *ptep, pte_t pte)
+{
+        /* XXX because of set_pmd_pte, this can be called on PT or PD layers */
+        vmi_check_page_type(__pa(ptep) >> PAGE_SHIFT, VMI_PAGE_PTE | VMI_PAGE_PD);
+        vmi_ops.set_pte(pte, ptep, VMI_PAGE_PT);
+}
+
+static void vmi_set_pte_at(struct mm_struct *mm, u32 addr, pte_t *ptep, pte_t pte)
+{
+        vmi_check_page_type(__pa(ptep) >> PAGE_SHIFT, VMI_PAGE_PTE);
+        vmi_ops.set_pte(pte, ptep, vmi_flags_addr(mm, addr, VMI_PAGE_PT, 0));
+}
+
+static void vmi_set_pmd(pmd_t *pmdp, pmd_t pmdval)
+{
+#ifdef CONFIG_X86_PAE
+        const pte_t pte = { pmdval.pmd, pmdval.pmd >> 32 };
+        vmi_check_page_type(__pa(pmdp) >> PAGE_SHIFT, VMI_PAGE_PMD);
+#else
+        const pte_t pte = { pmdval.pud.pgd.pgd };
+        vmi_check_page_type(__pa(pmdp) >> PAGE_SHIFT, VMI_PAGE_PGD);
+#endif
+        vmi_ops.set_pte(pte, (pte_t *)pmdp, VMI_PAGE_PD);
+}
+
+#ifdef CONFIG_X86_PAE
+
+static void vmi_set_pte_atomic(pte_t *ptep, pte_t pteval)
+{
+        /*
+         * XXX This is called from set_pmd_pte, but at both PT
+         * and PD layers so the VMI_PAGE_PT flag is wrong.  But
+         * it is only called for large page mapping changes,
+         * the Xen backend, doesn't support large pages, and the
+         * ESX backend doesn't depend on the flag.
+         */
+        set_64bit((unsigned long long *)ptep,pte_val(pteval));
+        vmi_ops.update_pte(ptep, VMI_PAGE_PT);
+}
+
+static void vmi_set_pte_present(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pte)
+{
+        vmi_check_page_type(__pa(ptep) >> PAGE_SHIFT, VMI_PAGE_PTE);
+        vmi_ops.set_pte(pte, ptep, vmi_flags_addr_defer(mm, addr, VMI_PAGE_PT, 1));
+}
+
+static void vmi_set_pud(pud_t *pudp, pud_t pudval)
+{
+        /* Um, eww */
+        const pte_t pte = { pudval.pgd.pgd, pudval.pgd.pgd >> 32 };
+        vmi_check_page_type(__pa(pudp) >> PAGE_SHIFT, VMI_PAGE_PGD);
+        vmi_ops.set_pte(pte, (pte_t *)pudp, VMI_PAGE_PDP);
+}
+
+static void vmi_pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
+{
+        const pte_t pte = { 0 };
+        vmi_check_page_type(__pa(ptep) >> PAGE_SHIFT, VMI_PAGE_PTE);
+        vmi_ops.set_pte(pte, ptep, vmi_flags_addr(mm, addr, VMI_PAGE_PT, 0));
+}
+
+void vmi_pmd_clear(pmd_t *pmd)
+{
+        const pte_t pte = { 0 };
+        vmi_check_page_type(__pa(pmd) >> PAGE_SHIFT, VMI_PAGE_PMD);
+        vmi_ops.set_pte(pte, (pte_t *)pmd, VMI_PAGE_PD);
+}
+#endif
+
+#ifdef CONFIG_SMP
+struct vmi_ap_state ap;
+extern void setup_pda(void);
+
+static void __init /* XXX cpu hotplug */
+vmi_startup_ipi_hook(int phys_apicid, unsigned long start_eip,
+                     unsigned long start_esp)
+{
+        /* Default everything to zero.  This is fine for most GPRs. */
+        memset(&ap, 0, sizeof(struct vmi_ap_state));
+
+        ap.gdtr_limit = GDT_SIZE - 1;
+        ap.gdtr_base = (unsigned long) get_cpu_gdt_table(phys_apicid);
+
+        ap.idtr_limit = IDT_ENTRIES * 8 - 1;
+        ap.idtr_base = (unsigned long) idt_table;
+
+        ap.ldtr = 0;
+
+        ap.cs = __KERNEL_CS;
+        ap.eip = (unsigned long) start_eip;
+        ap.ss = __KERNEL_DS;
+        ap.esp = (unsigned long) start_esp;
+
+        ap.ds = __USER_DS;
+        ap.es = __USER_DS;
+        ap.fs = __KERNEL_PDA;
+        ap.gs = 0;
+
+        ap.eflags = 0;
+
+        setup_pda();
+
+#ifdef CONFIG_X86_PAE
+        /* efer should match BSP efer. */
+        if (cpu_has_nx) {
+                unsigned l, h;
+                rdmsr(MSR_EFER, l, h);
+                ap.efer = (unsigned long long) h << 32 | l;
+        }
+#endif
+
+        ap.cr3 = __pa(swapper_pg_dir);
+        /* Protected mode, paging, AM, WP, NE, MP. */
+        ap.cr0 = 0x80050023;
+        ap.cr4 = mmu_cr4_features;
+        vmi_ops.set_initial_ap_state(__pa(&ap), phys_apicid);
+}
+#endif
+
+static inline int __init check_vmi_rom(struct vrom_header *rom)
+{
+        struct pci_header *pci;
+        struct pnp_header *pnp;
+        const char *manufacturer = "UNKNOWN";
+        const char *product = "UNKNOWN";
+        const char *license = "unspecified";
+
+        if (rom->rom_signature != 0xaa55)
+                return 0;
+        if (rom->vrom_signature != VMI_SIGNATURE)
+                return 0;
+        if (rom->api_version_maj != VMI_API_REV_MAJOR ||
+            rom->api_version_min+1 < VMI_API_REV_MINOR+1) {
+                printk(KERN_WARNING "VMI: Found mismatched rom version %d.%d\n",
+                                rom->api_version_maj,
+                                rom->api_version_min);
+                return 0;
+        }
+
+        /*
+         * Relying on the VMI_SIGNATURE field is not 100% safe, so check
+         * the PCI header and device type to make sure this is really a
+         * VMI device.
+         */
+        if (!rom->pci_header_offs) {
+                printk(KERN_WARNING "VMI: ROM does not contain PCI header.\n");
+                return 0;
+        }
+
+        pci = (struct pci_header *)((char *)rom+rom->pci_header_offs);
+        if (pci->vendorID != PCI_VENDOR_ID_VMWARE ||
+            pci->deviceID != PCI_DEVICE_ID_VMWARE_VMI) {
+                /* Allow it to run... anyways, but warn */
+                printk(KERN_WARNING "VMI: ROM from unknown manufacturer\n");
+        }
+
+        if (rom->pnp_header_offs) {
+                pnp = (struct pnp_header *)((char *)rom+rom->pnp_header_offs);
+                if (pnp->manufacturer_offset)
+                        manufacturer = (const char *)rom+pnp->manufacturer_offset;
+                if (pnp->product_offset)
+                        product = (const char *)rom+pnp->product_offset;
+        }
+
+        if (rom->license_offs)
+                license = (char *)rom+rom->license_offs;
+
+        printk(KERN_INFO "VMI: Found %s %s, API version %d.%d, ROM version %d.%d\n",
+                manufacturer, product,
+                rom->api_version_maj, rom->api_version_min,
+                pci->rom_version_maj, pci->rom_version_min);
+
+        license_gplok = license_is_gpl_compatible(license);
+        if (!license_gplok) {
+                printk(KERN_WARNING "VMI: ROM license '%s' taints kernel... "
+                       "inlining disabled\n",
+                       license);
+                add_taint(TAINT_PROPRIETARY_MODULE);
+        }
+        return 1;
+}
+
+/*
+ * Probe for the VMI option ROM
+ */
+static inline int __init probe_vmi_rom(void)
+{
+        unsigned long base;
+
+        /* VMI ROM is in option ROM area, check signature */
+        for (base = 0xC0000; base < 0xE0000; base += 2048) {
+                struct vrom_header *romstart;
+                romstart = (struct vrom_header *)isa_bus_to_virt(base);
+                if (check_vmi_rom(romstart)) {
+                        vmi_rom = romstart;
+                        return 1;
+                }
+        }
+        return 0;
+}
+
+/*
+ * VMI setup common to all processors
+ */
+void vmi_bringup(void)
+{
+        /* We must establish the lowmem mapping for MMU ops to work */
+        if (vmi_rom)
+                vmi_ops.set_linear_mapping(0, __PAGE_OFFSET, max_low_pfn, 0);
+}
+
+/*
+ * Return a pointer to the VMI function or a NOP stub
+ */
+static void *vmi_get_function(int vmicall)
+{
+        u64 reloc;
+        const struct vmi_relocation_info *rel = (struct vmi_relocation_info *)&reloc;
+        reloc = call_vrom_long_func(vmi_rom, get_reloc, vmicall);
+        BUG_ON(rel->type == VMI_RELOCATION_JUMP_REL);
+        if (rel->type == VMI_RELOCATION_CALL_REL)
+                return (void *)rel->eip;
+        else
+                return (void *)vmi_nop;
+}
+
+/*
+ * Helper macro for making the VMI paravirt-ops fill code readable.
+ * For unimplemented operations, fall back to default.
+ */
+#define para_fill(opname, vmicall)                              \
+do {                                                            \
+        reloc = call_vrom_long_func(vmi_rom, get_reloc,         \
+                                    VMI_CALL_##vmicall);        \
+        if (rel->type != VMI_RELOCATION_NONE) {                 \
+                BUG_ON(rel->type != VMI_RELOCATION_CALL_REL);   \
+                paravirt_ops.opname = (void *)rel->eip;         \
+        }                                                       \
+} while (0)
+
+/*
+ * Activate the VMI interface and switch into paravirtualized mode
+ */
+static inline int __init activate_vmi(void)
+{
+        short kernel_cs;
+        u64 reloc;
+        const struct vmi_relocation_info *rel = (struct vmi_relocation_info *)&reloc;
+
+        if (call_vrom_func(vmi_rom, vmi_init) != 0) {
+                printk(KERN_ERR "VMI ROM failed to initialize!");
+                return 0;
+        }
+        savesegment(cs, kernel_cs);
+
+        paravirt_ops.paravirt_enabled = 1;
+        paravirt_ops.kernel_rpl = kernel_cs & SEGMENT_RPL_MASK;
+
+        paravirt_ops.patch = vmi_patch;
+        paravirt_ops.name = "vmi";
+
+        /*
+         * Many of these operations are ABI compatible with VMI.
+         * This means we can fill in the paravirt-ops with direct
+         * pointers into the VMI ROM.  If the calling convention for
+         * these operations changes, this code needs to be updated.
+         *
+         * Exceptions
+         *  CPUID paravirt-op uses pointers, not the native ISA
+         *  halt has no VMI equivalent; all VMI halts are "safe"
+         *  no MSR support yet - just trap and emulate.  VMI uses the
+         *    same ABI as the native ISA, but Linux wants exceptions
+         *    from bogus MSR read / write handled
+         *  rdpmc is not yet used in Linux
+         */
+
+        /* CPUID is special, so very special */
+        reloc = call_vrom_long_func(vmi_rom, get_reloc, VMI_CALL_CPUID);
+        if (rel->type != VMI_RELOCATION_NONE) {
+                BUG_ON(rel->type != VMI_RELOCATION_CALL_REL);
+                vmi_ops.cpuid = (void *)rel->eip;
+                paravirt_ops.cpuid = vmi_cpuid;
+        }
+
+        para_fill(clts, CLTS);
+        para_fill(get_debugreg, GetDR);
+        para_fill(set_debugreg, SetDR);
+        para_fill(read_cr0, GetCR0);
+        para_fill(read_cr2, GetCR2);
+        para_fill(read_cr3, GetCR3);
+        para_fill(read_cr4, GetCR4);
+        para_fill(write_cr0, SetCR0);
+        para_fill(write_cr2, SetCR2);
+        para_fill(write_cr3, SetCR3);
+        para_fill(write_cr4, SetCR4);
+        para_fill(save_fl, GetInterruptMask);
+        para_fill(restore_fl, SetInterruptMask);
+        para_fill(irq_disable, DisableInterrupts);
+        para_fill(irq_enable, EnableInterrupts);
+        /* irq_save_disable !!! sheer pain */
+        patch_offset(&irq_save_disable_callout[IRQ_PATCH_INT_MASK],
+                     (char *)paravirt_ops.save_fl);
+        patch_offset(&irq_save_disable_callout[IRQ_PATCH_DISABLE],
+                     (char *)paravirt_ops.irq_disable);
+        para_fill(safe_halt, Halt);
+        para_fill(wbinvd, WBINVD);
+        /* paravirt_ops.read_msr = vmi_rdmsr */
+        /* paravirt_ops.write_msr = vmi_wrmsr */
+        para_fill(read_tsc, RDTSC);
+        /* paravirt_ops.rdpmc = vmi_rdpmc */
+
+        /* TR interface doesn't pass TR value */
+        reloc = call_vrom_long_func(vmi_rom, get_reloc, VMI_CALL_SetTR);
+        if (rel->type != VMI_RELOCATION_NONE) {
+                BUG_ON(rel->type != VMI_RELOCATION_CALL_REL);
+                vmi_ops.set_tr = (void *)rel->eip;
+                paravirt_ops.load_tr_desc = vmi_set_tr;
+        }
+
+        /* LDT is special, too */
+        reloc = call_vrom_long_func(vmi_rom, get_reloc, VMI_CALL_SetLDT);
+        if (rel->type != VMI_RELOCATION_NONE) {
+                BUG_ON(rel->type != VMI_RELOCATION_CALL_REL);
+                vmi_ops._set_ldt = (void *)rel->eip;
+                paravirt_ops.set_ldt = vmi_set_ldt;
+        }
+
+        para_fill(load_gdt, SetGDT);
+        para_fill(load_idt, SetIDT);
+        para_fill(store_gdt, GetGDT);
+        para_fill(store_idt, GetIDT);
+        para_fill(store_tr, GetTR);
+        paravirt_ops.load_tls = vmi_load_tls;
+        para_fill(write_ldt_entry, WriteLDTEntry);
+        para_fill(write_gdt_entry, WriteGDTEntry);
+        para_fill(write_idt_entry, WriteIDTEntry);
+        reloc = call_vrom_long_func(vmi_rom, get_reloc,
+                                    VMI_CALL_UpdateKernelStack);
+        if (rel->type != VMI_RELOCATION_NONE) {
+                BUG_ON(rel->type != VMI_RELOCATION_CALL_REL);
+                vmi_ops.set_kernel_stack = (void *)rel->eip;
+                paravirt_ops.load_esp0 = vmi_load_esp0;
+        }
+
+        para_fill(set_iopl_mask, SetIOPLMask);
+        paravirt_ops.io_delay = (void *)vmi_nop;
+        if (!disable_nodelay) {
+                paravirt_ops.const_udelay = (void *)vmi_nop;
+        }
+
+        para_fill(set_lazy_mode, SetLazyMode);
+
+        reloc = call_vrom_long_func(vmi_rom, get_reloc, VMI_CALL_FlushTLB);
+        if (rel->type != VMI_RELOCATION_NONE) {
+                vmi_ops.flush_tlb = (void *)rel->eip;
+                paravirt_ops.flush_tlb_user = vmi_flush_tlb_user;
+                paravirt_ops.flush_tlb_kernel = vmi_flush_tlb_kernel;
+        }
+        para_fill(flush_tlb_single, InvalPage);
+
+        /*
+         * Until a standard flag format can be agreed on, we need to
+         * implement these as wrappers in Linux.  Get the VMI ROM
+         * function pointers for the two backend calls.
+         */
+#ifdef CONFIG_X86_PAE
+        vmi_ops.set_pte = vmi_get_function(VMI_CALL_SetPxELong);
+        vmi_ops.update_pte = vmi_get_function(VMI_CALL_UpdatePxELong);
+#else
+        vmi_ops.set_pte = vmi_get_function(VMI_CALL_SetPxE);
+        vmi_ops.update_pte = vmi_get_function(VMI_CALL_UpdatePxE);
+#endif
+        vmi_ops.set_linear_mapping = vmi_get_function(VMI_CALL_SetLinearMapping);
+        vmi_ops.allocate_page = vmi_get_function(VMI_CALL_AllocatePage);
+        vmi_ops.release_page = vmi_get_function(VMI_CALL_ReleasePage);
+
+        paravirt_ops.alloc_pt = vmi_allocate_pt;
+        paravirt_ops.alloc_pd = vmi_allocate_pd;
+        paravirt_ops.alloc_pd_clone = vmi_allocate_pd_clone;
+        paravirt_ops.release_pt = vmi_release_pt;
+        paravirt_ops.release_pd = vmi_release_pd;
+        paravirt_ops.set_pte = vmi_set_pte;
+        paravirt_ops.set_pte_at = vmi_set_pte_at;
+        paravirt_ops.set_pmd = vmi_set_pmd;
+        paravirt_ops.pte_update = vmi_update_pte;
+        paravirt_ops.pte_update_defer = vmi_update_pte_defer;
+#ifdef CONFIG_X86_PAE
+        paravirt_ops.set_pte_atomic = vmi_set_pte_atomic;
+        paravirt_ops.set_pte_present = vmi_set_pte_present;
+        paravirt_ops.set_pud = vmi_set_pud;
+        paravirt_ops.pte_clear = vmi_pte_clear;
+        paravirt_ops.pmd_clear = vmi_pmd_clear;
+#endif
+        /*
+         * These MUST always be patched.  Don't support indirect jumps
+         * through these operations, as the VMI interface may use either
+         * a jump or a call to get to these operations, depending on
+         * the backend.  They are performance critical anyway, so requiring
+         * a patch is not a big problem.
+         */
+        paravirt_ops.irq_enable_sysexit = (void *)0xfeedbab0;
+        paravirt_ops.iret = (void *)0xbadbab0;
+
+#ifdef CONFIG_SMP
+        paravirt_ops.startup_ipi_hook = vmi_startup_ipi_hook;
+        vmi_ops.set_initial_ap_state = vmi_get_function(VMI_CALL_SetInitialAPState);
+#endif
+
+#ifdef CONFIG_X86_LOCAL_APIC
+        paravirt_ops.apic_read = vmi_get_function(VMI_CALL_APICRead);
+        paravirt_ops.apic_write = vmi_get_function(VMI_CALL_APICWrite);
+        paravirt_ops.apic_write_atomic = vmi_get_function(VMI_CALL_APICWrite);
+#endif
+
+        /*
+         * Alternative instruction rewriting doesn't happen soon enough
+         * to convert VMI_IRET to a call instead of a jump; so we have
+         * to do this before IRQs get reenabled.  Fortunately, it is
+         * idempotent.
+         */
+        apply_paravirt(__start_parainstructions, __stop_parainstructions);
+
+        vmi_bringup();
+
+        return 1;
+}
+
+#undef para_fill
+
+void __init vmi_init(void)
+{
+        unsigned long flags;
+
+        if (!vmi_rom)
+                probe_vmi_rom();
+        else
+                check_vmi_rom(vmi_rom);
+
+        /* In case probing for or validating the ROM failed, basil */
+        if (!vmi_rom)
+                return;
+
+        reserve_top_address(-vmi_rom->virtual_top);
+
+        local_irq_save(flags);
+        activate_vmi();
+#ifdef CONFIG_SMP
+        no_timer_check = 1;
+#endif
+        local_irq_restore(flags & X86_EFLAGS_IF);
+}
+
+static int __init parse_vmi(char *arg)
+{
+        if (!arg)
+                return -EINVAL;
+
+        if (!strcmp(arg, "disable_nodelay"))
+                disable_nodelay = 1;
+        else if (!strcmp(arg, "disable_pge")) {
+                clear_bit(X86_FEATURE_PGE, boot_cpu_data.x86_capability);
+                disable_pge = 1;
+        } else if (!strcmp(arg, "disable_pse")) {
+                clear_bit(X86_FEATURE_PSE, boot_cpu_data.x86_capability);
+                disable_pse = 1;
+        } else if (!strcmp(arg, "disable_sep")) {
+                clear_bit(X86_FEATURE_SEP, boot_cpu_data.x86_capability);
+                disable_sep = 1;
+        } else if (!strcmp(arg, "disable_tsc")) {
+                clear_bit(X86_FEATURE_TSC, boot_cpu_data.x86_capability);
+                disable_tsc = 1;
+        } else if (!strcmp(arg, "disable_mtrr")) {
+                clear_bit(X86_FEATURE_MTRR, boot_cpu_data.x86_capability);
+                disable_mtrr = 1;
+        }
+        return 0;
+}
+
+early_param("vmi", parse_vmi);