Re: (subset) [PATCH v9 00/24] KVM: s390: Introduce arm64 KVM

[Steffen Eiden]

On Thu, Oct 01, 2026 at 12:04:51PM +0100, Marc Zyngier wrote:
> On Wed, 30 Sep 2026 19:34:15 +0200, Steffen Eiden wrote:
> > Introduce arm-on-s390. Enable KVM-accelerated ARM CPU virtualisation on s390.
> > 
> > The new KVM functionally depends on KVM/vfio: Use file-based reference
> > counting for KVM [5] The series itself should apply w/o those.
> > 
> > For the original, now partially outdated, cover letter, have a look at versions
> > one to three [1].
> > 
> > [...]
> 
> Applied to next, thanks!
> 
> [05/24] arm64: ptrace: Use constants for compat register numbers
>         commit: 295d3df9b1e425099a4eb37954a02c4a08fdb496
> [06/24] arm64: sysreg: Convert SPSR_ELx to automatic register generation
>         commit: d3d78520068779779e1ed7aa0dd8a3ce63e1ca43
> [07/24] KVM: arm64: Access elements of vcpu_gp_regs individually
>         commit: 29d92585ab987bb80b1e78d811aaea2a8db86e62
> [08/24] KVM: arm64: Use accessor functions for core regs
>         commit: 89ed62818f10e38e64fea46d43ee6455a1beb647
> [09/24] arm64: Prepare sharing arm64 headers with s390
>         commit: df6a70516adec8b7f5fa49e1755d8ee33d980d9c
> [10/24] arm64: Share arm64 headers with s390
>         commit: c7e18ba462536e870b0ff4deca581babcac9135b
> [11/24] KVM: arm64: Share arm64 code with s390
>         commit: dcb776bfcccc9662001a75b99dbfbef55f46eb31
> 
> Note that there were a few conflicts. Please check that I resolved
> them correctly.


After rebasing on those the arm-on-s390 part does not build anymore :( 

We are missing the definition of
static __always_inline bool esr_abt_is_s1ptw(unsigned long esr)


quick fix: 

on top of [10/24]  arm64: Share arm64 headers with s390

diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h
index bf35cbe8ddcb..0708f792c631 100644
--- a/arch/arm64/include/asm/kvm_emulate.h
+++ b/arch/arm64/include/asm/kvm_emulate.h
@@ -367,10 +367,13 @@ static __always_inline u64 kvm_vcpu_get_esr(const struct kvm_vcpu *vcpu)
        return vcpu->arch.fault.esr_el2;
 }

+#if ARM64_S390_COMMON == 1
 static __always_inline bool esr_abt_is_s1ptw(unsigned long esr)
 {
        return esr & ESR_ELx_S1PTW;
 }
+
+#endif /* ARM64_S390_COMMON == 1 */

 static __always_inline bool esr_abt_is_exec_fault(unsigned long esr)
 {



A cleaner solution it to move this defenition just below  
void kvm_vcpu_wfi(struct kvm_vcpu *vcpu) in 
[09/24] arm64: Prepare sharing arm64 headers with s390
and expand the shared region in the following patch.

I can send the two fixup patches as a reply here for this tomorrow or later today if you want. 


	Steffen