Re: [PATCH v2 26/50] KVM: PPC: Move processor compatibility check to module init
From: Sean Christopherson
Date: Thu Dec 01 2022 - 11:38:36 EST
On Thu, Dec 01, 2022, Michael Ellerman wrote:
> Sean Christopherson <seanjc@xxxxxxxxxx> writes:
> > Move KVM PPC's compatibility checks to their respective module_init()
> > hooks, there's no need to wait until KVM's common compat check, nor is
> > there a need to perform the check on every CPU (provided by common KVM's
> > hook), as the compatibility checks operate on global data.
> >
> > arch/powerpc/include/asm/cputable.h: extern struct cpu_spec *cur_cpu_spec;
> > arch/powerpc/kvm/book3s.c: return 0
> > arch/powerpc/kvm/e500.c: strcmp(cur_cpu_spec->cpu_name, "e500v2")
> > arch/powerpc/kvm/e500mc.c: strcmp(cur_cpu_spec->cpu_name, "e500mc")
> > strcmp(cur_cpu_spec->cpu_name, "e5500")
> > strcmp(cur_cpu_spec->cpu_name, "e6500")
>
> I'm not sure that output is really useful in the change log unless you
> explain more about what it is.
Agreed, I got lazy. I'll write a proper description.
> > diff --git a/arch/powerpc/kvm/e500mc.c b/arch/powerpc/kvm/e500mc.c
> > index 57e0ad6a2ca3..795667f7ebf0 100644
> > --- a/arch/powerpc/kvm/e500mc.c
> > +++ b/arch/powerpc/kvm/e500mc.c
> > @@ -388,6 +388,10 @@ static int __init kvmppc_e500mc_init(void)
> > {
> > int r;
> >
> > + r = kvmppc_e500mc_check_processor_compat();
> > + if (r)
> > + return kvmppc_e500mc;
>
> This doesn't build:
>
> linux/arch/powerpc/kvm/e500mc.c: In function ‘kvmppc_e500mc_init’:
> linux/arch/powerpc/kvm/e500mc.c:391:13: error: implicit declaration of function ‘kvmppc_e500mc_check_processor_compat’; did you mean ‘kvmppc_core_check_processor_compat’? [-Werror=implicit-function-declaration]
> 391 | r = kvmppc_e500mc_check_processor_compat();
> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> | kvmppc_core_check_processor_compat
> linux/arch/powerpc/kvm/e500mc.c:393:24: error: ‘kvmppc_e500mc’ undeclared (first use in this function); did you mean ‘kvm_ops_e500mc’?
> 393 | return kvmppc_e500mc;
> | ^~~~~~~~~~~~~
> | kvm_ops_e500mc
> linux/arch/powerpc/kvm/e500mc.c:393:24: note: each undeclared identifier is reported only once for each function it appears in
Huh, CONFIG_PPC_E500MC got unselected in the config I use to compile test this
flavor. I suspect I botched an oldconfig at some point.
Anyways, fixed that and the bugs.
Thanks much!
--
Subject: [PATCH] KVM: PPC: Move processor compatibility check to module init
Move KVM PPC's compatibility checks to their respective module_init()
hooks, there's no need to wait until KVM's common compat check, nor is
there a need to perform the check on every CPU (provided by common KVM's
hook). The compatibility checks are either a nop (Book3S), or simply
check the CPU name stored in the global CPU spec (e500 and e500mc).
Cc: Fabiano Rosas <farosas@xxxxxxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
arch/powerpc/include/asm/kvm_ppc.h | 1 -
arch/powerpc/kvm/book3s.c | 10 ----------
arch/powerpc/kvm/e500.c | 4 ++--
arch/powerpc/kvm/e500mc.c | 6 +++++-
arch/powerpc/kvm/powerpc.c | 2 +-
5 files changed, 8 insertions(+), 15 deletions(-)
diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
index bfacf12784dd..51a1824b0a16 100644
--- a/arch/powerpc/include/asm/kvm_ppc.h
+++ b/arch/powerpc/include/asm/kvm_ppc.h
@@ -118,7 +118,6 @@ extern int kvmppc_xlate(struct kvm_vcpu *vcpu, ulong eaddr,
extern int kvmppc_core_vcpu_create(struct kvm_vcpu *vcpu);
extern void kvmppc_core_vcpu_free(struct kvm_vcpu *vcpu);
extern int kvmppc_core_vcpu_setup(struct kvm_vcpu *vcpu);
-extern int kvmppc_core_check_processor_compat(void);
extern int kvmppc_core_vcpu_translate(struct kvm_vcpu *vcpu,
struct kvm_translation *tr);
diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
index 6d525285dbe8..87283a0e33d8 100644
--- a/arch/powerpc/kvm/book3s.c
+++ b/arch/powerpc/kvm/book3s.c
@@ -999,16 +999,6 @@ int kvmppc_h_logical_ci_store(struct kvm_vcpu *vcpu)
}
EXPORT_SYMBOL_GPL(kvmppc_h_logical_ci_store);
-int kvmppc_core_check_processor_compat(void)
-{
- /*
- * We always return 0 for book3s. We check
- * for compatibility while loading the HV
- * or PR module
- */
- return 0;
-}
-
int kvmppc_book3s_hcall_implemented(struct kvm *kvm, unsigned long hcall)
{
return kvm->arch.kvm_ops->hcall_implemented(hcall);
diff --git a/arch/powerpc/kvm/e500.c b/arch/powerpc/kvm/e500.c
index c8b2b4478545..0ea61190ec04 100644
--- a/arch/powerpc/kvm/e500.c
+++ b/arch/powerpc/kvm/e500.c
@@ -314,7 +314,7 @@ static void kvmppc_core_vcpu_put_e500(struct kvm_vcpu *vcpu)
kvmppc_booke_vcpu_put(vcpu);
}
-int kvmppc_core_check_processor_compat(void)
+static int kvmppc_e500_check_processor_compat(void)
{
int r;
@@ -507,7 +507,7 @@ static int __init kvmppc_e500_init(void)
unsigned long handler_len;
unsigned long max_ivor = 0;
- r = kvmppc_core_check_processor_compat();
+ r = kvmppc_e500_check_processor_compat();
if (r)
goto err_out;
diff --git a/arch/powerpc/kvm/e500mc.c b/arch/powerpc/kvm/e500mc.c
index 57e0ad6a2ca3..4564aa27edcf 100644
--- a/arch/powerpc/kvm/e500mc.c
+++ b/arch/powerpc/kvm/e500mc.c
@@ -168,7 +168,7 @@ static void kvmppc_core_vcpu_put_e500mc(struct kvm_vcpu *vcpu)
kvmppc_booke_vcpu_put(vcpu);
}
-int kvmppc_core_check_processor_compat(void)
+int kvmppc_e500mc_check_processor_compat(void)
{
int r;
@@ -388,6 +388,10 @@ static int __init kvmppc_e500mc_init(void)
{
int r;
+ r = kvmppc_e500mc_check_processor_compat();
+ if (r)
+ goto err_out;
+
r = kvmppc_booke_init();
if (r)
goto err_out;
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index 5faf69421f13..d44b85ba8cef 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -442,7 +442,7 @@ int kvm_arch_hardware_enable(void)
int kvm_arch_check_processor_compat(void *opaque)
{
- return kvmppc_core_check_processor_compat();
+ return 0;
}
int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
base-commit: 00e4493db7c6163d48d5b45034d1a77e16a1c8dc
--