6.1-stable review patch. If anyone has any objections, please let me know.
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From: Brian Gerst brgerst@gmail.com
[ Upstream commit 1ab7b5ed44ba9bce581e225f40219b793bc779d6 ]
Move the upcall handler to Xen-specific files.
No functional changes.
Signed-off-by: Brian Gerst brgerst@gmail.com Signed-off-by: Ingo Molnar mingo@kernel.org Reviewed-by: Juergen Gross jgross@suse.com Reviewed-by: Sohil Mehta sohil.mehta@intel.com Cc: Andy Lutomirski luto@kernel.org Cc: H. Peter Anvin hpa@zytor.com Cc: Linus Torvalds torvalds@linux-foundation.org Cc: Josh Poimboeuf jpoimboe@redhat.com Link: https://lore.kernel.org/r/20250314151220.862768-2-brgerst@gmail.com Stable-dep-of: e5aff444e3a7 ("x86/xen: Fix sparse warning in enlighten_pv.c") Signed-off-by: Sasha Levin sashal@kernel.org --- arch/x86/entry/common.c | 72 ------------------------------------- arch/x86/xen/enlighten_pv.c | 69 +++++++++++++++++++++++++++++++++++ 2 files changed, 69 insertions(+), 72 deletions(-)
diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c index e72dac092245..3c88bdf96e7a 100644 --- a/arch/x86/entry/common.c +++ b/arch/x86/entry/common.c @@ -20,11 +20,6 @@ #include <linux/syscalls.h> #include <linux/uaccess.h>
-#ifdef CONFIG_XEN_PV -#include <xen/xen-ops.h> -#include <xen/events.h> -#endif - #include <asm/apic.h> #include <asm/desc.h> #include <asm/traps.h> @@ -346,70 +341,3 @@ SYSCALL_DEFINE0(ni_syscall) { return -ENOSYS; } - -#ifdef CONFIG_XEN_PV -#ifndef CONFIG_PREEMPTION -/* - * Some hypercalls issued by the toolstack can take many 10s of - * seconds. Allow tasks running hypercalls via the privcmd driver to - * be voluntarily preempted even if full kernel preemption is - * disabled. - * - * Such preemptible hypercalls are bracketed by - * xen_preemptible_hcall_begin() and xen_preemptible_hcall_end() - * calls. - */ -DEFINE_PER_CPU(bool, xen_in_preemptible_hcall); -EXPORT_SYMBOL_GPL(xen_in_preemptible_hcall); - -/* - * In case of scheduling the flag must be cleared and restored after - * returning from schedule as the task might move to a different CPU. - */ -static __always_inline bool get_and_clear_inhcall(void) -{ - bool inhcall = __this_cpu_read(xen_in_preemptible_hcall); - - __this_cpu_write(xen_in_preemptible_hcall, false); - return inhcall; -} - -static __always_inline void restore_inhcall(bool inhcall) -{ - __this_cpu_write(xen_in_preemptible_hcall, inhcall); -} -#else -static __always_inline bool get_and_clear_inhcall(void) { return false; } -static __always_inline void restore_inhcall(bool inhcall) { } -#endif - -static void __xen_pv_evtchn_do_upcall(struct pt_regs *regs) -{ - struct pt_regs *old_regs = set_irq_regs(regs); - - inc_irq_stat(irq_hv_callback_count); - - xen_evtchn_do_upcall(); - - set_irq_regs(old_regs); -} - -__visible noinstr void xen_pv_evtchn_do_upcall(struct pt_regs *regs) -{ - irqentry_state_t state = irqentry_enter(regs); - bool inhcall; - - instrumentation_begin(); - run_sysvec_on_irqstack_cond(__xen_pv_evtchn_do_upcall, regs); - - inhcall = get_and_clear_inhcall(); - if (inhcall && !WARN_ON_ONCE(state.exit_rcu)) { - irqentry_exit_cond_resched(); - instrumentation_end(); - restore_inhcall(inhcall); - } else { - instrumentation_end(); - irqentry_exit(regs, state); - } -} -#endif /* CONFIG_XEN_PV */ diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c index ee8f452cc58b..9a54049744bf 100644 --- a/arch/x86/xen/enlighten_pv.c +++ b/arch/x86/xen/enlighten_pv.c @@ -71,6 +71,7 @@ #include <asm/mwait.h> #include <asm/pci_x86.h> #include <asm/cpu.h> +#include <asm/irq_stack.h> #ifdef CONFIG_X86_IOPL_IOPERM #include <asm/io_bitmap.h> #endif @@ -96,6 +97,44 @@ void *xen_initial_gdt; static int xen_cpu_up_prepare_pv(unsigned int cpu); static int xen_cpu_dead_pv(unsigned int cpu);
+#ifndef CONFIG_PREEMPTION +/* + * Some hypercalls issued by the toolstack can take many 10s of + * seconds. Allow tasks running hypercalls via the privcmd driver to + * be voluntarily preempted even if full kernel preemption is + * disabled. + * + * Such preemptible hypercalls are bracketed by + * xen_preemptible_hcall_begin() and xen_preemptible_hcall_end() + * calls. + */ +DEFINE_PER_CPU(bool, xen_in_preemptible_hcall); +EXPORT_SYMBOL_GPL(xen_in_preemptible_hcall); + +/* + * In case of scheduling the flag must be cleared and restored after + * returning from schedule as the task might move to a different CPU. + */ +static __always_inline bool get_and_clear_inhcall(void) +{ + bool inhcall = __this_cpu_read(xen_in_preemptible_hcall); + + __this_cpu_write(xen_in_preemptible_hcall, false); + return inhcall; +} + +static __always_inline void restore_inhcall(bool inhcall) +{ + __this_cpu_write(xen_in_preemptible_hcall, inhcall); +} + +#else + +static __always_inline bool get_and_clear_inhcall(void) { return false; } +static __always_inline void restore_inhcall(bool inhcall) { } + +#endif + struct tls_descs { struct desc_struct desc[3]; }; @@ -597,6 +636,36 @@ DEFINE_IDTENTRY_RAW(xenpv_exc_machine_check) } #endif
+static void __xen_pv_evtchn_do_upcall(struct pt_regs *regs) +{ + struct pt_regs *old_regs = set_irq_regs(regs); + + inc_irq_stat(irq_hv_callback_count); + + xen_evtchn_do_upcall(); + + set_irq_regs(old_regs); +} + +__visible noinstr void xen_pv_evtchn_do_upcall(struct pt_regs *regs) +{ + irqentry_state_t state = irqentry_enter(regs); + bool inhcall; + + instrumentation_begin(); + run_sysvec_on_irqstack_cond(__xen_pv_evtchn_do_upcall, regs); + + inhcall = get_and_clear_inhcall(); + if (inhcall && !WARN_ON_ONCE(state.exit_rcu)) { + irqentry_exit_cond_resched(); + instrumentation_end(); + restore_inhcall(inhcall); + } else { + instrumentation_end(); + irqentry_exit(regs, state); + } +} + struct trap_array_entry { void (*orig)(void); void (*xen)(void);