From: Jan Beulich <jbeulich@suse.com>
Subject: x86: replace reset_stack_and_jump_nolp()
Move the necessary check into check_for_livepatch_work(), rather than
mostly duplicating reset_stack_and_jump() for this purpose. This is to
prevent an inflation of reset_stack_and_jump() flavors.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
---
Of course instead of adding the check right into
check_for_livepatch_work(), a wrapper could be introduced.
--- a/xen/arch/x86/domain.c
+++ b/xen/arch/x86/domain.c
@@ -192,7 +192,7 @@ static void noreturn continue_idle_domai
{
/* Idle vcpus might be attached to non-idle units! */
if ( !is_idle_domain(v->sched_unit->domain) )
- reset_stack_and_jump_nolp(guest_idle_loop);
+ reset_stack_and_jump(guest_idle_loop);
reset_stack_and_jump(idle_loop);
}
--- a/xen/arch/x86/hvm/svm/svm.c
+++ b/xen/arch/x86/hvm/svm/svm.c
@@ -1036,7 +1036,7 @@ static void noreturn svm_do_resume(struc
hvm_do_resume(v);
- reset_stack_and_jump_nolp(svm_asm_do_resume);
+ reset_stack_and_jump(svm_asm_do_resume);
}
void svm_vmenter_helper(const struct cpu_user_regs *regs)
--- a/xen/arch/x86/hvm/vmx/vmcs.c
+++ b/xen/arch/x86/hvm/vmx/vmcs.c
@@ -1909,7 +1909,7 @@ void vmx_do_resume(struct vcpu *v)
if ( host_cr4 != read_cr4() )
__vmwrite(HOST_CR4, read_cr4());
- reset_stack_and_jump_nolp(vmx_asm_do_vmentry);
+ reset_stack_and_jump(vmx_asm_do_vmentry);
}
static inline unsigned long vmr(unsigned long field)
--- a/xen/arch/x86/pv/domain.c
+++ b/xen/arch/x86/pv/domain.c
@@ -113,7 +113,7 @@ static int parse_pcid(const char *s)
static void noreturn continue_nonidle_domain(struct vcpu *v)
{
check_wakeup_from_wait();
- reset_stack_and_jump_nolp(ret_from_intr);
+ reset_stack_and_jump(ret_from_intr);
}
static int setup_compat_l4(struct vcpu *v)
--- a/xen/arch/x86/setup.c
+++ b/xen/arch/x86/setup.c
@@ -676,7 +676,7 @@ static void __init noreturn reinit_bsp_s
asm volatile ("setssbsy" ::: "memory");
}
- reset_stack_and_jump_nolp(init_done);
+ reset_stack_and_jump(init_done);
}
/*
--- a/xen/common/livepatch.c
+++ b/xen/common/livepatch.c
@@ -1635,6 +1635,11 @@ void check_for_livepatch_work(void)
s_time_t timeout;
unsigned long flags;
+ /* Only do any work when invoked in truly idle state. */
+ if ( system_state != SYS_STATE_active ||
+ !is_idle_domain(current->sched_unit->domain) )
+ return;
+
/* Fast path: no work to do. */
if ( !per_cpu(work_to_do, cpu ) )
return;
--- a/xen/include/asm-x86/current.h
+++ b/xen/include/asm-x86/current.h
@@ -155,13 +155,13 @@ unsigned long get_stack_dump_bottom (uns
# define SHADOW_STACK_WORK ""
#endif
-#define switch_stack_and_jump(fn, instr) \
+#define reset_stack_and_jump(fn) \
({ \
unsigned int tmp; \
__asm__ __volatile__ ( \
SHADOW_STACK_WORK \
"mov %[stk], %%rsp;" \
- instr \
+ CHECK_FOR_LIVEPATCH_WORK \
"jmp %c[fun];" \
: [val] "=&r" (tmp), \
[ssp] "=&r" (tmp) \
@@ -176,12 +176,6 @@ unsigned long get_stack_dump_bottom (uns
unreachable(); \
})
-#define reset_stack_and_jump(fn) \
- switch_stack_and_jump(fn, CHECK_FOR_LIVEPATCH_WORK)
-
-#define reset_stack_and_jump_nolp(fn) \
- switch_stack_and_jump(fn, "")
-
/*
* Which VCPU's state is currently running on each CPU?
* This is not necesasrily the same as 'current' as a CPU may be