Commit 22cc5ca5 authored by Kiryl Shutsemau's avatar Kiryl Shutsemau Committed by Ingo Molnar
Browse files

x86/paravirt: Move halt paravirt calls under CONFIG_PARAVIRT 



CONFIG_PARAVIRT_XXL is mainly defined/used by XEN PV guests. For
other VM guest types, features supported under CONFIG_PARAVIRT
are self sufficient. CONFIG_PARAVIRT mainly provides support for
TLB flush operations and time related operations.

For TDX guest as well, paravirt calls under CONFIG_PARVIRT meets
most of its requirement except the need of HLT and SAFE_HLT
paravirt calls, which is currently defined under
CONFIG_PARAVIRT_XXL.

Since enabling CONFIG_PARAVIRT_XXL is too bloated for TDX guest
like platforms, move HLT and SAFE_HLT paravirt calls under
CONFIG_PARAVIRT.

Moving HLT and SAFE_HLT paravirt calls are not fatal and should not
break any functionality for current users of CONFIG_PARAVIRT.

Fixes: bfe6ed0c ("x86/tdx: Add HLT support for TDX guests")
Co-developed-by: default avatarKuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Signed-off-by: default avatarKuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Signed-off-by: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: default avatarVishal Annapurve <vannapurve@google.com>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Reviewed-by: default avatarAndi Kleen <ak@linux.intel.com>
Reviewed-by: default avatarTony Luck <tony.luck@intel.com>
Reviewed-by: default avatarJuergen Gross <jgross@suse.com>
Tested-by: default avatarRyan Afranji <afranji@google.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: stable@kernel.org
Link: https://lore.kernel.org/r/20250228014416.3925664-2-vannapurve@google.com
parent 0d86c239

arch/x86/include/asm/irqflags.h

+22 −18
Original line number Diff line number Diff line
@@ -76,6 +76,28 @@ static __always_inline void native_local_irq_restore(unsigned long flags) 


#endif



#ifndef CONFIG_PARAVIRT

#ifndef __ASSEMBLY__

/*

 * Used in the idle loop; sti takes one instruction cycle

 * to complete:

 */

static __always_inline void arch_safe_halt(void)

{

	native_safe_halt();

}



/*

 * Used when interrupts are already enabled or to

 * shutdown the processor:

 */

static __always_inline void halt(void)

{

	native_halt();

}

#endif /* __ASSEMBLY__ */

#endif /* CONFIG_PARAVIRT */



#ifdef CONFIG_PARAVIRT_XXL

#include <asm/paravirt.h>

#else
@@ -97,24 +119,6 @@ static __always_inline void arch_local_irq_enable(void) 
	native_irq_enable();

}



/*

 * Used in the idle loop; sti takes one instruction cycle

 * to complete:

 */

static __always_inline void arch_safe_halt(void)

{

	native_safe_halt();

}



/*

 * Used when interrupts are already enabled or to

 * shutdown the processor:

 */

static __always_inline void halt(void)

{

	native_halt();

}



/*

 * For spinlocks, etc:

 */

arch/x86/include/asm/paravirt.h

+10 −10
Original line number Diff line number Diff line
@@ -102,6 +102,16 @@ static inline void notify_page_enc_status_changed(unsigned long pfn, 
	PVOP_VCALL3(mmu.notify_page_enc_status_changed, pfn, npages, enc);

}



static __always_inline void arch_safe_halt(void)

{

	PVOP_VCALL0(irq.safe_halt);

}



static inline void halt(void)

{

	PVOP_VCALL0(irq.halt);

}



#ifdef CONFIG_PARAVIRT_XXL

static inline void load_sp0(unsigned long sp0)

{
@@ -165,16 +175,6 @@ static inline void __write_cr4(unsigned long x) 
	PVOP_VCALL1(cpu.write_cr4, x);

}



static __always_inline void arch_safe_halt(void)

{

	PVOP_VCALL0(irq.safe_halt);

}



static inline void halt(void)

{

	PVOP_VCALL0(irq.halt);

}



static inline u64 paravirt_read_msr(unsigned msr)

{

	return PVOP_CALL1(u64, cpu.read_msr, msr);

arch/x86/include/asm/paravirt_types.h

+1 −2
Original line number Diff line number Diff line
@@ -120,10 +120,9 @@ struct pv_irq_ops { 
	struct paravirt_callee_save save_fl;

	struct paravirt_callee_save irq_disable;

	struct paravirt_callee_save irq_enable;



#endif

	void (*safe_halt)(void);

	void (*halt)(void);

#endif

} __no_randomize_layout;



struct pv_mmu_ops {

arch/x86/kernel/paravirt.c

+8 −6
Original line number Diff line number Diff line
@@ -75,6 +75,11 @@ void paravirt_set_sched_clock(u64 (*func)(void)) 
	static_call_update(pv_sched_clock, func);

}



static noinstr void pv_native_safe_halt(void)

{

	native_safe_halt();

}



#ifdef CONFIG_PARAVIRT_XXL

static noinstr void pv_native_write_cr2(unsigned long val)

{
@@ -100,11 +105,6 @@ static noinstr void pv_native_set_debugreg(int regno, unsigned long val) 
{

	native_set_debugreg(regno, val);

}



static noinstr void pv_native_safe_halt(void)

{

	native_safe_halt();

}

#endif



struct pv_info pv_info = {
@@ -161,9 +161,11 @@ struct paravirt_patch_template pv_ops = { 
	.irq.save_fl		= __PV_IS_CALLEE_SAVE(pv_native_save_fl),

	.irq.irq_disable	= __PV_IS_CALLEE_SAVE(pv_native_irq_disable),

	.irq.irq_enable		= __PV_IS_CALLEE_SAVE(pv_native_irq_enable),

#endif /* CONFIG_PARAVIRT_XXL */



	/* Irq HLT ops. */

	.irq.safe_halt		= pv_native_safe_halt,

	.irq.halt		= native_halt,

#endif /* CONFIG_PARAVIRT_XXL */



	/* Mmu ops. */

	.mmu.flush_tlb_user	= native_flush_tlb_local,