From d3561b7fa0fb0fc583bab0eeda32bec9e4c4056d Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Thu, 7 Dec 2006 02:14:07 +0100 Subject: [PATCH] paravirt: header and stubs for paravirtualisation Create a paravirt.h header for all the critical operations which need to be replaced with hypervisor calls, and include that instead of defining native operations, when CONFIG_PARAVIRT. This patch does the dumbest possible replacement of paravirtualized instructions: calls through a "paravirt_ops" structure. Currently these are function implementations of native hardware: hypervisors will override the ops structure with their own variants. All the pv-ops functions are declared "fastcall" so that a specific register-based ABI is used, to make inlining assember easier. And: +From: Andy Whitcroft The paravirt ops introduce a 'weak' attribute onto memory_setup(). Code ordering leads to the following warnings on x86: arch/i386/kernel/setup.c:651: warning: weak declaration of `memory_setup' after first use results in unspecified behavior Move memory_setup() to avoid this. Signed-off-by: Rusty Russell Signed-off-by: Chris Wright Signed-off-by: Andi Kleen Cc: Jeremy Fitzhardinge Cc: Zachary Amsden Signed-off-by: Andrew Morton Signed-off-by: Andy Whitcroft --- include/asm-i386/spinlock.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'include/asm-i386/spinlock.h') diff --git a/include/asm-i386/spinlock.h b/include/asm-i386/spinlock.h index c18b71fae6b..dea60709db2 100644 --- a/include/asm-i386/spinlock.h +++ b/include/asm-i386/spinlock.h @@ -7,8 +7,12 @@ #include #include +#ifdef CONFIG_PARAVIRT +#include +#else #define CLI_STRING "cli" #define STI_STRING "sti" +#endif /* CONFIG_PARAVIRT */ /* * Your basic SMP spinlocks, allowing only a single CPU anywhere -- cgit v1.2.3-18-g5258 From 139ec7c416248b9ea227d21839235344edfee1e0 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Thu, 7 Dec 2006 02:14:08 +0100 Subject: [PATCH] paravirt: Patch inline replacements for paravirt intercepts It turns out that the most called ops, by several orders of magnitude, are the interrupt manipulation ops. These are obvious candidates for patching, so mark them up and create infrastructure for it. The method used is that the ops structure has a patch function, which is called for each place which needs to be patched: this returns a number of instructions (the rest are NOP-padded). Usually we can spare a register (%eax) for the binary patched code to use, but in a couple of critical places in entry.S we can't: we make the clobbers explicit at the call site, and manually clobber the allowed registers in debug mode as an extra check. And: Don't abuse CONFIG_DEBUG_KERNEL, add CONFIG_DEBUG_PARAVIRT. And: AK: Fix warnings in x86-64 alternative.c build And: AK: Fix compilation with defconfig And: ^From: Andrew Morton Some binutlises still like to emit references to __stop_parainstructions and __start_parainstructions. And: AK: Fix warnings about unused variables when PARAVIRT is disabled. Signed-off-by: Rusty Russell Signed-off-by: Jeremy Fitzhardinge Signed-off-by: Chris Wright Signed-off-by: Zachary Amsden Signed-off-by: Andi Kleen Signed-off-by: Andrew Morton --- include/asm-i386/spinlock.h | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) (limited to 'include/asm-i386/spinlock.h') diff --git a/include/asm-i386/spinlock.h b/include/asm-i386/spinlock.h index dea60709db2..d3bcebed60c 100644 --- a/include/asm-i386/spinlock.h +++ b/include/asm-i386/spinlock.h @@ -12,6 +12,8 @@ #else #define CLI_STRING "cli" #define STI_STRING "sti" +#define CLI_STI_CLOBBERS +#define CLI_STI_INPUT_ARGS #endif /* CONFIG_PARAVIRT */ /* @@ -57,25 +59,28 @@ static inline void __raw_spin_lock_flags(raw_spinlock_t *lock, unsigned long fla { asm volatile( "\n1:\t" - LOCK_PREFIX " ; decb %0\n\t" + LOCK_PREFIX " ; decb %[slock]\n\t" "jns 5f\n" "2:\t" - "testl $0x200, %1\n\t" + "testl $0x200, %[flags]\n\t" "jz 4f\n\t" STI_STRING "\n" "3:\t" "rep;nop\n\t" - "cmpb $0, %0\n\t" + "cmpb $0, %[slock]\n\t" "jle 3b\n\t" CLI_STRING "\n\t" "jmp 1b\n" "4:\t" "rep;nop\n\t" - "cmpb $0, %0\n\t" + "cmpb $0, %[slock]\n\t" "jg 1b\n\t" "jmp 4b\n" "5:\n\t" - : "+m" (lock->slock) : "r" (flags) : "memory"); + : [slock] "+m" (lock->slock) + : [flags] "r" (flags) + CLI_STI_INPUT_ARGS + : "memory" CLI_STI_CLOBBERS); } #endif -- cgit v1.2.3-18-g5258