From 134764ed6e12d9f99b3de68b8aaeae1ba842d91c Mon Sep 17 00:00:00 2001 From: Aravinda Prasad Date: Thu, 11 May 2017 16:32:48 +0530 Subject: KVM: PPC: Book3S HV: Add new capability to control MCE behaviour This introduces a new KVM capability to control how KVM behaves on machine check exception (MCE) in HV KVM guests. If this capability has not been enabled, KVM redirects machine check exceptions to guest's 0x200 vector, if the address in error belongs to the guest. With this capability enabled, KVM will cause a guest exit with the exit reason indicating an NMI. The new capability is required to avoid problems if a new kernel/KVM is used with an old QEMU, running a guest that doesn't issue "ibm,nmi-register". As old QEMU does not understand the NMI exit type, it treats it as a fatal error. However, the guest could have handled the machine check error if the exception was delivered to guest's 0x200 interrupt vector instead of NMI exit in case of old QEMU. [paulus@ozlabs.org - Reworded the commit message to be clearer, enable only on HV KVM.] Signed-off-by: Aravinda Prasad Reviewed-by: David Gibson Signed-off-by: Mahesh Salgaonkar Signed-off-by: Paul Mackerras --- include/uapi/linux/kvm.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/uapi') diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 577429a95ad8..89bc145b4051 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -895,6 +895,7 @@ struct kvm_ppc_resize_hpt { #define KVM_CAP_SPAPR_TCE_VFIO 142 #define KVM_CAP_X86_GUEST_MWAIT 143 #define KVM_CAP_ARM_USER_IRQ 144 +#define KVM_CAP_PPC_FWNMI 145 #ifdef KVM_CAP_IRQ_ROUTING -- cgit v1.2.3 From 2ed4f9dd19c0f76f7fb56c4b201696d29149325c Mon Sep 17 00:00:00 2001 From: Paul Mackerras Date: Wed, 21 Jun 2017 16:01:27 +1000 Subject: KVM: PPC: Book3S HV: Add capability to report possible virtual SMT modes Now that userspace can set the virtual SMT mode by enabling the KVM_CAP_PPC_SMT capability, it is useful for userspace to be able to query the set of possible virtual SMT modes. This provides a new capability, KVM_CAP_PPC_SMT_POSSIBLE, to provide this information. The return value is a bitmap of possible modes, with bit N set if virtual SMT mode 2^N is available. That is, 1 indicates SMT1 is available, 2 indicates that SMT2 is available, 3 indicates that both SMT1 and SMT2 are available, and so on. Signed-off-by: Paul Mackerras --- Documentation/virtual/kvm/api.txt | 11 +++++++++++ arch/powerpc/kvm/powerpc.c | 10 ++++++++++ include/uapi/linux/kvm.h | 1 + 3 files changed, 22 insertions(+) (limited to 'include/uapi') diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index 1531a3cd548f..63875dbb6ef5 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -4010,6 +4010,8 @@ be 0. A successful call to enable this capability will result in vsmt_mode being returned when the KVM_CAP_PPC_SMT capability is subsequently queried for the VM. This capability is only supported by HV KVM, and can only be set before any VCPUs have been created. +The KVM_CAP_PPC_SMT_POSSIBLE capability indicates which virtual SMT +modes are available. 7.12 KVM_CAP_PPC_FWNMI @@ -4183,3 +4185,12 @@ Currently the following bits are defined for the device_irq_level bitmap: Future versions of kvm may implement additional events. These will get indicated by returning a higher number from KVM_CHECK_EXTENSION and will be listed above. + +8.10 KVM_CAP_PPC_SMT_POSSIBLE + +Architectures: ppc + +Querying this capability returns a bitmap indicating the possible +virtual SMT modes that can be set using KVM_CAP_PPC_SMT. If bit N +(counting from the right) is set, then a virtual SMT mode of 2^N is +available. diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c index ccaa7a407c15..b14736f3870b 100644 --- a/arch/powerpc/kvm/powerpc.c +++ b/arch/powerpc/kvm/powerpc.c @@ -566,6 +566,16 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) r = threads_per_subcore; } break; + case KVM_CAP_PPC_SMT_POSSIBLE: + r = 1; + if (hv_enabled) { + if (!cpu_has_feature(CPU_FTR_ARCH_300)) + r = ((threads_per_subcore << 1) - 1); + else + /* P9 can emulate dbells, so allow any mode */ + r = 8 | 4 | 2 | 1; + } + break; case KVM_CAP_PPC_RMA: r = 0; break; diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 89bc145b4051..36ea74aa3422 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -896,6 +896,7 @@ struct kvm_ppc_resize_hpt { #define KVM_CAP_X86_GUEST_MWAIT 143 #define KVM_CAP_ARM_USER_IRQ 144 #define KVM_CAP_PPC_FWNMI 145 +#define KVM_CAP_PPC_SMT_POSSIBLE 146 #ifdef KVM_CAP_IRQ_ROUTING -- cgit v1.2.3