diff options
| author | Amit Machhiwal <amachhiw@linux.ibm.com> | 2025-04-26 00:26:41 +0530 |
|---|---|---|
| committer | Madhavan Srinivasan <maddy@linux.ibm.com> | 2025-05-12 10:19:29 +0530 |
| commit | ccdb36cbe65fe05fd5349c7ee5a59e53be7fe195 (patch) | |
| tree | 66130ecdfed17ba10a7fd775956cabc2bcaab701 | |
| parent | f9cb1476ade41ba859e6f41323e76284b297d7c2 (diff) | |
KVM: PPC: Book3S HV: Fix IRQ map warnings with XICS on pSeries KVM Guest
The commit 9576730d0e6e ("KVM: PPC: select IRQ_BYPASS_MANAGER") enabled
IRQ_BYPASS_MANAGER when CONFIG_KVM was set. Subsequently, commit
c57875f5f9be ("KVM: PPC: Book3S HV: Enable IRQ bypass") enabled IRQ
bypass and added the necessary callbacks to create/remove the mappings
between host real IRQ and the guest GSI.
The availability of IRQ bypass is determined by the arch-specific
function kvm_arch_has_irq_bypass(), which invokes
kvmppc_irq_bypass_add_producer_hv(). This function, in turn, calls
kvmppc_set_passthru_irq_hv() to create a mapping in the passthrough IRQ
map, associating a host IRQ to a guest GSI.
However, when a pSeries KVM guest (L2) is booted within an LPAR (L1)
with the kernel boot parameter `xive=off`, it defaults to using emulated
XICS controller. As an attempt to establish host IRQ to guest GSI
mappings via kvmppc_set_passthru_irq() on a PCI device hotplug
(passhthrough) operation fail, returning -ENOENT. This failure occurs
because only interrupts with EOI operations handled through OPAL calls
(verified via is_pnv_opal_msi()) are currently supported.
These mapping failures lead to below repeated warnings in the L1 host:
[ 509.220349] kvmppc_set_passthru_irq_hv: Could not assign IRQ map for (58,4970)
[ 509.220368] kvmppc_set_passthru_irq (irq 58, gsi 4970) fails: -2
[ 509.220376] vfio-pci 0015:01:00.0: irq bypass producer (token 0000000090bc635b) registration fails: -2
...
[ 509.291781] vfio-pci 0015:01:00.0: irq bypass producer (token 000000003822eed8) registration fails: -2
Fix this by restricting IRQ bypass enablement on pSeries systems by
making the IRQ bypass callbacks unavailable when running on pSeries
platform.
Signed-off-by: Amit Machhiwal <amachhiw@linux.ibm.com>
Tested-by: Gautam Menghani <gautam@linux.ibm.com>
Reviewed-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20250425185641.1611857-1-amachhiw@linux.ibm.com
| -rw-r--r-- | arch/powerpc/kvm/book3s_hv.c | 20 |
1 files changed, 16 insertions, 4 deletions
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index 19f4d298dd17..7667563fb9ff 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -6541,10 +6541,6 @@ static struct kvmppc_ops kvm_ops_hv = { .fast_vcpu_kick = kvmppc_fast_vcpu_kick_hv, .arch_vm_ioctl = kvm_arch_vm_ioctl_hv, .hcall_implemented = kvmppc_hcall_impl_hv, -#ifdef CONFIG_KVM_XICS - .irq_bypass_add_producer = kvmppc_irq_bypass_add_producer_hv, - .irq_bypass_del_producer = kvmppc_irq_bypass_del_producer_hv, -#endif .configure_mmu = kvmhv_configure_mmu, .get_rmmu_info = kvmhv_get_rmmu_info, .set_smt_mode = kvmhv_set_smt_mode, @@ -6662,6 +6658,22 @@ static int kvmppc_book3s_init_hv(void) return r; } +#if defined(CONFIG_KVM_XICS) + /* + * IRQ bypass is supported only for interrupts whose EOI operations are + * handled via OPAL calls. Therefore, register IRQ bypass handlers + * exclusively for PowerNV KVM when booted with 'xive=off', indicating + * the use of the emulated XICS interrupt controller. + */ + if (!kvmhv_on_pseries()) { + pr_info("KVM-HV: Enabling IRQ bypass\n"); + kvm_ops_hv.irq_bypass_add_producer = + kvmppc_irq_bypass_add_producer_hv; + kvm_ops_hv.irq_bypass_del_producer = + kvmppc_irq_bypass_del_producer_hv; + } +#endif + kvm_ops_hv.owner = THIS_MODULE; kvmppc_hv_ops = &kvm_ops_hv; |