[PATCH 8/9] Vmi apic ops.diff

From: Zachary Amsden
Date: Thu Mar 01 2007 - 21:56:57 EST

Use para_fill instead of directly setting the APIC ops to the result of the
vmi_get_function call - this allows one to implement a VMI ROM without
implementing APIC functions, just using the native APIC functions.

While doing this, I realized that there is a lot more cleanup that should
have been done. Basically, we should never assume that the ROM implements
a specific set of functions, and always allow fallback to the native
implementation.

This is critical for future compatibility.

Signed-off-by: Anthony Liguori <anthony@xxxxxxxxxxxxx>
Signed-off-by: Zachary Amsden <zach@xxxxxxxxxx>

diff -r 0ba8434a5c7e arch/i386/kernel/vmi.c
--- a/arch/i386/kernel/vmi.c Thu Mar 01 16:49:27 2007 -0800
+++ b/arch/i386/kernel/vmi.c Thu Mar 01 16:49:33 2007 -0800
@@ -54,6 +54,7 @@ static int disable_tsc;
static int disable_tsc;
static int disable_mtrr;
static int disable_noidle;
+static int disable_vmi_timer;

/* Cached VMI operations */
struct {
@@ -662,12 +663,12 @@ void vmi_bringup(void)
void vmi_bringup(void)
{
/* We must establish the lowmem mapping for MMU ops to work */
- if (vmi_rom)
+ if (vmi_ops.set_linear_mapping)
vmi_ops.set_linear_mapping(0, __PAGE_OFFSET, max_low_pfn, 0);
}

/*
- * Return a pointer to the VMI function or a NOP stub
+ * Return a pointer to a VMI function or NULL if unimplemented
*/
static void *vmi_get_function(int vmicall)
{
@@ -678,12 +679,13 @@ static void *vmi_get_function(int vmical
if (rel->type == VMI_RELOCATION_CALL_REL)
return (void *)rel->eip;
else
- return (void *)vmi_nop;
+ return NULL;
}

/*
* Helper macro for making the VMI paravirt-ops fill code readable.
- * For unimplemented operations, fall back to default.
+ * For unimplemented operations, fall back to default, unless nop
+ * is returned by the ROM.
*/
#define para_fill(opname, vmicall) \
do { \
@@ -692,8 +694,28 @@ do { \
if (rel->type != VMI_RELOCATION_NONE) { \
BUG_ON(rel->type != VMI_RELOCATION_CALL_REL); \
paravirt_ops.opname = (void *)rel->eip; \
+ } else if (rel->type == VMI_RELOCATION_NOP) \
+ paravirt_ops.opname = (void *)vmi_nop; \
+} while (0)
+
+/*
+ * Helper macro for making the VMI paravirt-ops fill code readable.
+ * For cached operations which do not match the VMI ROM ABI and must
+ * go through a tranlation stub. Ignore NOPs, since it is not clear
+ * a NOP * VMI function corresponds to a NOP paravirt-op when the
+ * functions are not in 1-1 correspondence.
+ */
+#define para_wrap(opname, wrapper, cache, vmicall) \
+do { \
+ reloc = call_vrom_long_func(vmi_rom, get_reloc, \
+ VMI_CALL_##vmicall); \
+ BUG_ON(rel->type == VMI_RELOCATION_JUMP_REL); \
+ if (rel->type == VMI_RELOCATION_CALL_REL) { \
+ paravirt_ops.opname = wrapper; \
+ vmi_ops.cache = (void *)rel->eip; \
} \
} while (0)
+

/*
* Activate the VMI interface and switch into paravirtualized mode
@@ -731,13 +753,8 @@ static inline int __init activate_vmi(vo
* 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;
- }
+ /* CPUID is special, so very special it gets wrapped like a present */
+ para_wrap(cpuid, vmi_cpuid, cpuid, CPUID);

para_fill(clts, CLTS);
para_fill(get_debugreg, GetDR);
@@ -754,6 +771,7 @@ static inline int __init activate_vmi(vo
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);
@@ -761,26 +779,18 @@ static inline int __init activate_vmi(vo
(char *)paravirt_ops.irq_disable);

para_fill(wbinvd, WBINVD);
+ para_fill(read_tsc, RDTSC);
+
+ /* The following we emulate with trap and emulate for now */
/* 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;
- }
+ /* TR interface doesn't pass TR value, wrap */
+ para_wrap(load_tr_desc, vmi_set_tr, set_tr, SetTR);

/* 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_wrap(set_ldt, vmi_set_ldt, _set_ldt, SetLDT);

para_fill(load_gdt, SetGDT);
para_fill(load_idt, SetIDT);
@@ -791,25 +801,14 @@ static inline int __init activate_vmi(vo
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_wrap(load_esp0, vmi_load_esp0, set_kernel_stack, UpdateKernelStack);
para_fill(set_iopl_mask, SetIOPLMask);
- paravirt_ops.io_delay = (void *)vmi_nop;
-
+ para_fill(io_delay, IODelay);
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;
- }
+ /* user and kernel flush are just handled with different flags to FlushTLB */
+ para_wrap(flush_tlb_user, vmi_flush_tlb_user, flush_tlb, FlushTLB);
+ para_wrap(flush_tlb_kernel, vmi_flush_tlb_kernel, flush_tlb, FlushTLB);
para_fill(flush_tlb_single, InvalPage);

/*
@@ -824,28 +823,40 @@ static inline int __init activate_vmi(vo
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);
+
+ if (vmi_ops.set_pte) {
+ paravirt_ops.set_pte = vmi_set_pte;
+ paravirt_ops.set_pte_at = vmi_set_pte_at;
+ paravirt_ops.set_pmd = vmi_set_pmd;
+#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
+ }
+
+ if (vmi_ops.update_pte) {
+ paravirt_ops.pte_update = vmi_update_pte;
+ paravirt_ops.pte_update_defer = vmi_update_pte_defer;
+ }
+
vmi_ops.allocate_page = vmi_get_function(VMI_CALL_AllocatePage);
+ if (vmi_ops.allocate_page) {
+ paravirt_ops.alloc_pt = vmi_allocate_pt;
+ paravirt_ops.alloc_pd = vmi_allocate_pd;
+ paravirt_ops.alloc_pd_clone = vmi_allocate_pd_clone;
+ }
+
vmi_ops.release_page = vmi_get_function(VMI_CALL_ReleasePage);
-
- paravirt_ops.map_pt_hook = vmi_map_pt_hook;
- 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
+ if (vmi_ops.release_page) {
+ paravirt_ops.release_pt = vmi_release_pt;
+ paravirt_ops.release_pd = vmi_release_pd;
+ }
+ para_wrap(map_pt_hook, vmi_map_pt_hook, set_linear_mapping,
+ SetLinearMapping);
+
/*
* These MUST always be patched. Don't support indirect jumps
* through these operations, as the VMI interface may use either
@@ -857,21 +868,20 @@ static inline int __init activate_vmi(vo
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);
+ para_wrap(startup_ipi_hook, vmi_startup_ipi_hook, set_initial_ap_state, 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);
+ para_fill(apic_read, APICRead);
+ para_fill(apic_write, APICWrite);
+ para_fill(apic_write_atomic, APICWrite);
#endif

/*
* Check for VMI timer functionality by probing for a cycle frequency method
*/
reloc = call_vrom_long_func(vmi_rom, get_reloc, VMI_CALL_GetCycleFrequency);
- if (rel->type != VMI_RELOCATION_NONE) {
+ if (!disable_vmi_timer && rel->type != VMI_RELOCATION_NONE) {
vmi_timer_ops.get_cycle_frequency = (void *)rel->eip;
vmi_timer_ops.get_cycle_counter =
vmi_get_function(VMI_CALL_GetCycleCounter);
@@ -891,13 +901,19 @@ static inline int __init activate_vmi(vo
#endif
paravirt_ops.get_scheduled_cycles = vmi_get_sched_cycles;
paravirt_ops.get_cpu_khz = vmi_cpu_khz;
- }
- if (!disable_noidle)
+
+ /* We have true wallclock functions; disable CMOS clock sync */
+ no_sync_cmos_clock = 1;
+ } else {
+ disable_noidle = 1;
+ disable_vmi_timer = 1;
+ }
+
+ /* No idle HZ mode only works if VMI timer and no idle is enabled */
+ if (disable_noidle || disable_vmi_timer)
para_fill(safe_halt, Halt);
- else {
- vmi_ops.halt = vmi_get_function(VMI_CALL_Halt);
- paravirt_ops.safe_halt = vmi_safe_halt;
- }
+ else
+ para_wrap(safe_halt, vmi_safe_halt, halt, Halt);

/*
* Alternative instruction rewriting doesn't happen soon enough
@@ -933,10 +949,9 @@ void __init vmi_init(void)
activate_vmi();

#ifdef CONFIG_X86_IO_APIC
+ /* This is virtual hardware; timer routing is wired correctly */
no_timer_check = 1;
#endif
- no_sync_cmos_clock = 1;
-
local_irq_restore(flags & X86_EFLAGS_IF);
}

@@ -960,6 +975,9 @@ static int __init parse_vmi(char *arg)
} else if (!strcmp(arg, "disable_mtrr")) {
clear_bit(X86_FEATURE_MTRR, boot_cpu_data.x86_capability);
disable_mtrr = 1;
+ } else if (!strcmp(arg, "disable_timer")) {
+ disable_vmi_timer = 1;
+ disable_noidle = 1;
} else if (!strcmp(arg, "disable_noidle"))
disable_noidle = 1;
return 0;
diff -r 0ba8434a5c7e include/asm-i386/vmi.h
--- a/include/asm-i386/vmi.h Thu Mar 01 16:49:27 2007 -0800
+++ b/include/asm-i386/vmi.h Thu Mar 01 16:49:33 2007 -0800
@@ -97,6 +97,7 @@
#define VMI_CALL_SetInitialAPState 62
#define VMI_CALL_APICWrite 63
#define VMI_CALL_APICRead 64
+#define VMI_CALL_IODelay 65
#define VMI_CALL_SetLazyMode 73

/*
-
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