From: Paul Mackerras paulus@ozlabs.org
commit 2ad7a27deaf6d78545d97ab80874584f6990360e upstream.
There are some POWER9 machines where the OPAL firmware does not support the OPAL_XIVE_GET_QUEUE_STATE and OPAL_XIVE_SET_QUEUE_STATE calls. The impact of this is that a guest using XIVE natively will not be able to be migrated successfully. On the source side, the get_attr operation on the KVM native device for the KVM_DEV_XIVE_GRP_EQ_CONFIG attribute will fail; on the destination side, the set_attr operation for the same attribute will fail.
This adds tests for the existence of the OPAL get/set queue state functions, and if they are not supported, the XIVE-native KVM device is not created and the KVM_CAP_PPC_IRQ_XIVE capability returns false. Userspace can then either provide a software emulation of XIVE, or else tell the guest that it does not have a XIVE controller available to it.
Cc: stable@vger.kernel.org # v5.2+ Fixes: 3fab2d10588e ("KVM: PPC: Book3S HV: XIVE: Activate XIVE exploitation mode") Reviewed-by: David Gibson david@gibson.dropbear.id.au Reviewed-by: Cédric Le Goater clg@kaod.org Signed-off-by: Paul Mackerras paulus@ozlabs.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/powerpc/include/asm/kvm_ppc.h | 1 + arch/powerpc/include/asm/xive.h | 1 + arch/powerpc/kvm/book3s.c | 8 +++++--- arch/powerpc/kvm/book3s_xive_native.c | 5 +++++ arch/powerpc/kvm/powerpc.c | 3 ++- arch/powerpc/sysdev/xive/native.c | 7 +++++++ 6 files changed, 21 insertions(+), 4 deletions(-)
--- a/arch/powerpc/include/asm/kvm_ppc.h +++ b/arch/powerpc/include/asm/kvm_ppc.h @@ -598,6 +598,7 @@ extern int kvmppc_xive_native_get_vp(str union kvmppc_one_reg *val); extern int kvmppc_xive_native_set_vp(struct kvm_vcpu *vcpu, union kvmppc_one_reg *val); +extern bool kvmppc_xive_native_supported(void);
#else static inline int kvmppc_xive_set_xive(struct kvm *kvm, u32 irq, u32 server, --- a/arch/powerpc/include/asm/xive.h +++ b/arch/powerpc/include/asm/xive.h @@ -127,6 +127,7 @@ extern int xive_native_get_queue_state(u extern int xive_native_set_queue_state(u32 vp_id, uint32_t prio, u32 qtoggle, u32 qindex); extern int xive_native_get_vp_state(u32 vp_id, u64 *out_state); +extern bool xive_native_has_queue_state_support(void);
#else
--- a/arch/powerpc/kvm/book3s.c +++ b/arch/powerpc/kvm/book3s.c @@ -1083,9 +1083,11 @@ static int kvmppc_book3s_init(void) if (xics_on_xive()) { kvmppc_xive_init_module(); kvm_register_device_ops(&kvm_xive_ops, KVM_DEV_TYPE_XICS); - kvmppc_xive_native_init_module(); - kvm_register_device_ops(&kvm_xive_native_ops, - KVM_DEV_TYPE_XIVE); + if (kvmppc_xive_native_supported()) { + kvmppc_xive_native_init_module(); + kvm_register_device_ops(&kvm_xive_native_ops, + KVM_DEV_TYPE_XIVE); + } } else #endif kvm_register_device_ops(&kvm_xics_ops, KVM_DEV_TYPE_XICS); --- a/arch/powerpc/kvm/book3s_xive_native.c +++ b/arch/powerpc/kvm/book3s_xive_native.c @@ -1171,6 +1171,11 @@ int kvmppc_xive_native_set_vp(struct kvm return 0; }
+bool kvmppc_xive_native_supported(void) +{ + return xive_native_has_queue_state_support(); +} + static int xive_native_debug_show(struct seq_file *m, void *private) { struct kvmppc_xive *xive = m->private; --- a/arch/powerpc/kvm/powerpc.c +++ b/arch/powerpc/kvm/powerpc.c @@ -561,7 +561,8 @@ int kvm_vm_ioctl_check_extension(struct * a POWER9 processor) and the PowerNV platform, as * nested is not yet supported. */ - r = xive_enabled() && !!cpu_has_feature(CPU_FTR_HVMODE); + r = xive_enabled() && !!cpu_has_feature(CPU_FTR_HVMODE) && + kvmppc_xive_native_supported(); break; #endif
--- a/arch/powerpc/sysdev/xive/native.c +++ b/arch/powerpc/sysdev/xive/native.c @@ -811,6 +811,13 @@ int xive_native_set_queue_state(u32 vp_i } EXPORT_SYMBOL_GPL(xive_native_set_queue_state);
+bool xive_native_has_queue_state_support(void) +{ + return opal_check_token(OPAL_XIVE_GET_QUEUE_STATE) && + opal_check_token(OPAL_XIVE_SET_QUEUE_STATE); +} +EXPORT_SYMBOL_GPL(xive_native_has_queue_state_support); + int xive_native_get_vp_state(u32 vp_id, u64 *out_state) { __be64 state;