From 23a60f834406c8e3805328b630d09d5546b460c1 Mon Sep 17 00:00:00 2001 From: Collin Walling Date: Mon, 22 Jun 2020 11:46:36 -0400 Subject: s390/kvm: diagnose 0x318 sync and reset DIAGNOSE 0x318 (diag318) sets information regarding the environment the VM is running in (Linux, z/VM, etc) and is observed via firmware/service events. This is a privileged s390x instruction that must be intercepted by SIE. Userspace handles the instruction as well as migration. Data is communicated via VCPU register synchronization. The Control Program Name Code (CPNC) is stored in the SIE block. The CPNC along with the Control Program Version Code (CPVC) are stored in the kvm_vcpu_arch struct. This data is reset on load normal and clear resets. Signed-off-by: Collin Walling Reviewed-by: Janosch Frank Acked-by: Cornelia Huck Reviewed-by: David Hildenbrand Link: https://lore.kernel.org/r/20200622154636.5499-3-walling@linux.ibm.com [borntraeger@de.ibm.com: fix sync_reg position] Signed-off-by: Christian Borntraeger --- 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 4fdf30316582..35cdb4307904 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -1031,6 +1031,7 @@ struct kvm_ppc_resize_hpt { #define KVM_CAP_PPC_SECURE_GUEST 181 #define KVM_CAP_HALT_POLL 182 #define KVM_CAP_ASYNC_PF_INT 183 +#define KVM_CAP_S390_DIAG318 184 #ifdef KVM_CAP_IRQ_ROUTING -- cgit From 1aa561b1a4c0ae2a9a9b9c21a84b5ca66b4775d8 Mon Sep 17 00:00:00 2001 From: Jim Mattson Date: Wed, 3 Jun 2020 16:56:21 -0700 Subject: kvm: x86: Add "last CPU" to some KVM_EXIT information More often than not, a failed VM-entry in an x86 production environment is induced by a defective CPU. To help identify the bad hardware, include the id of the last logical CPU to run a vCPU in the information provided to userspace on a KVM exit for failed VM-entry or for KVM internal errors not associated with emulation. The presence of this additional information is indicated by a new capability, KVM_CAP_LAST_CPU. Signed-off-by: Jim Mattson Reviewed-by: Oliver Upton Reviewed-by: Peter Shier Message-Id: <20200603235623.245638-5-jmattson@google.com> Signed-off-by: Paolo Bonzini --- include/uapi/linux/kvm.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/uapi') diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 4fdf30316582..ff9b335620d0 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -289,6 +289,7 @@ struct kvm_run { /* KVM_EXIT_FAIL_ENTRY */ struct { __u64 hardware_entry_failure_reason; + __u32 cpu; } fail_entry; /* KVM_EXIT_EXCEPTION */ struct { @@ -1031,6 +1032,7 @@ struct kvm_ppc_resize_hpt { #define KVM_CAP_PPC_SECURE_GUEST 181 #define KVM_CAP_HALT_POLL 182 #define KVM_CAP_ASYNC_PF_INT 183 +#define KVM_CAP_LAST_CPU 184 #ifdef KVM_CAP_IRQ_ROUTING -- cgit From 3edd68399dc155b80335244c8c2673eaa652931a Mon Sep 17 00:00:00 2001 From: Mohammed Gamal Date: Fri, 10 Jul 2020 17:48:11 +0200 Subject: KVM: x86: Add a capability for GUEST_MAXPHYADDR < HOST_MAXPHYADDR support This patch adds a new capability KVM_CAP_SMALLER_MAXPHYADDR which allows userspace to query if the underlying architecture would support GUEST_MAXPHYADDR < HOST_MAXPHYADDR and hence act accordingly (e.g. qemu can decide if it should warn for -cpu ..,phys-bits=X) The complications in this patch are due to unexpected (but documented) behaviour we see with NPF vmexit handling in AMD processor. If SVM is modified to add guest physical address checks in the NPF and guest #PF paths, we see the followning error multiple times in the 'access' test in kvm-unit-tests: test pte.p pte.36 pde.p: FAIL: pte 2000021 expected 2000001 Dump mapping: address: 0x123400000000 ------L4: 24c3027 ------L3: 24c4027 ------L2: 24c5021 ------L1: 1002000021 This is because the PTE's accessed bit is set by the CPU hardware before the NPF vmexit. This is handled completely by hardware and cannot be fixed in software. Therefore, availability of the new capability depends on a boolean variable allow_smaller_maxphyaddr which is set individually by VMX and SVM init routines. On VMX it's always set to true, on SVM it's only set to true when NPT is not enabled. CC: Tom Lendacky CC: Babu Moger Signed-off-by: Mohammed Gamal Message-Id: <20200710154811.418214-10-mgamal@redhat.com> Signed-off-by: Paolo Bonzini --- include/uapi/linux/kvm.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/uapi') diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index ff9b335620d0..2c73dcfb3dbb 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -1033,6 +1033,8 @@ struct kvm_ppc_resize_hpt { #define KVM_CAP_HALT_POLL 182 #define KVM_CAP_ASYNC_PF_INT 183 #define KVM_CAP_LAST_CPU 184 +#define KVM_CAP_SMALLER_MAXPHYADDR 185 + #ifdef KVM_CAP_IRQ_ROUTING -- cgit