From: "Kirill A. Shutemov" kirill.shutemov@linux.intel.com

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: bfe6ed0c6727 ("x86/tdx: Add HLT support for TDX guests") Co-developed-by: Kuppuswamy Sathyanarayanan sathyanarayanan.kuppuswamy@linux.intel.com Signed-off-by: Kuppuswamy Sathyanarayanan sathyanarayanan.kuppuswamy@linux.intel.com Signed-off-by: Kirill A. Shutemov kirill.shutemov@linux.intel.com Signed-off-by: Vishal Annapurve vannapurve@google.com Signed-off-by: Ingo Molnar mingo@kernel.org Reviewed-by: Andi Kleen ak@linux.intel.com Reviewed-by: Tony Luck tony.luck@intel.com Reviewed-by: Juergen Gross jgross@suse.com Tested-by: Ryan 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 --- 6.12.23 fails to build with the following error if CONFIG_XEN_PV is not set:

arch/x86/coco/tdx/tdx.c: In function ‘tdx_early_init’: arch/x86/coco/tdx/tdx.c:1080:19: error: ‘struct pv_irq_ops’ has no member named ‘safe_halt’ 1080 | pv_ops.irq.safe_halt = tdx_safe_halt; | ^ arch/x86/coco/tdx/tdx.c:1081:19: error: ‘struct pv_irq_ops’ has no member named ‘halt’ 1081 | pv_ops.irq.halt = tdx_halt; | ^

This is because XEN_PV selects PARAVIRT_XXL, and 'safe_halt' and 'halt' are only defined for pv_irq_ops if PARAVIRT_XXL is defined.

The build breakage was introduced in 6.12.23 by stable commit 805e3ce5e0e3 which is a backport of 9f98a4f4e721 ("x86/tdx: Fix arch_safe_halt() execution for TDX VMs").

Consider picking up upstream commit 22cc5ca5de52 ("x86/paravirt: Move halt paravirt calls under CONFIG_PARAVIRT") for stable 6.12.y which fixes the build regression by moving 'safe_halt' and 'halt' out from under the PARAVIRT_XXL config.

This patch is 22cc5ca5de52 backported to 6.12.23. There were a couple of merge conflicts due to the missing upstream commits below:

29188c160061 ("x86/paravirt: Remove the WBINVD callback") 3101900218d7 ("x86/paravirt: Remove unused paravirt_disable_iospace()")

I wasn't sure if it was appropriate to pull those to stable as well and the merge conflicts were trivial.

Thanks!

Signed-off-by: Brett Mastbergen bmastbergen@ciq.com --- arch/x86/include/asm/irqflags.h | 40 +++++++++++++++++++---------------- arch/x86/include/asm/paravirt.h | 20 +++++++++--------- arch/x86/include/asm/paravirt_types.h | 3 +-- arch/x86/kernel/paravirt.c | 13 +++++++----- 4 files changed, 41 insertions(+), 35 deletions(-)

diff --git a/arch/x86/include/asm/irqflags.h b/arch/x86/include/asm/irqflags.h index cf7fc2b8e3ce1f4e5f5703ae9fbb5a7e1182ad4f..1c2db11a2c3cb9a289d80d4900b9933275d1eea6 100644 --- a/arch/x86/include/asm/irqflags.h +++ b/arch/x86/include/asm/irqflags.h @@ -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: */ diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h index d4eb9e1d61b8ef8a3fc3a2510b0615ea93c11cb8..75d4c994f5e2a5dcbc2edbf7eed617de4a141fa0 100644 --- a/arch/x86/include/asm/paravirt.h +++ b/arch/x86/include/asm/paravirt.h @@ -107,6 +107,16 @@ 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) { @@ -170,16 +180,6 @@ 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); -} - extern noinstr void pv_native_wbinvd(void);

static __always_inline void wbinvd(void) diff --git a/arch/x86/include/asm/paravirt_types.h b/arch/x86/include/asm/paravirt_types.h index 8d4fbe1be489549ad33c968c2132bdbaf739b871..9334fdd1f6350231af7089802dfb94daa1653965 100644 --- a/arch/x86/include/asm/paravirt_types.h +++ b/arch/x86/include/asm/paravirt_types.h @@ -122,10 +122,9 @@ 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 { diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c index fec38153355581215eb93b6301ae90b6f0bd06c5..0c1b915d7efac895b2c8be67eb3b84b998d00fbc 100644 --- a/arch/x86/kernel/paravirt.c +++ b/arch/x86/kernel/paravirt.c @@ -100,6 +100,11 @@ int paravirt_disable_iospace(void) return request_resource(&ioport_resource, &reserve_ioports); }

+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) { @@ -121,10 +126,6 @@ noinstr void pv_native_wbinvd(void) native_wbinvd(); }

-static noinstr void pv_native_safe_halt(void) -{ - native_safe_halt(); -} #endif

struct pv_info pv_info = { @@ -182,9 +183,11 @@ 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,

--- base-commit: 83b4161a63b87ce40d9f24f09b5b006f63d95b7c change-id: 20250415-stable_fixup-c7b936473f53

Best regards,