[PATCH 3/5 V5] Add ioctl for KVMCLOCK_GUEST_STOPPED
From: Eric B Munson <hidden>
Date: 2011-12-05 20:20:43
Also in:
kvm, lkml
Subsystem:
documentation, kernel virtual machine (kvm), kernel virtual machine for x86 (kvm/x86), the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Jonathan Corbet, Paolo Bonzini, Sean Christopherson, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
Now that we have a flag that will tell the guest it was suspended, create an interface for that communication using a KVM ioctl. Signed-off-by: Eric B Munson <redacted> Cc: mingo@redhat.com Cc: hpa@zytor.com Cc: arnd@arndb.de Cc: ryanh@linux.vnet.ibm.com Cc: aliguori@us.ibm.com Cc: mtosatti@redhat.com Cc: jeremy.fitzhardinge@citrix.com Cc: levinsasha928@gmail.com Cc: Jan Kiszka <jan.kiszka@siemens.com> Cc: kvm@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: x86@kernel.org Cc: linux-kernel@vger.kernel.org --- Changes from V4: Rename KVM_GUEST_PAUSED to KVMCLOCK_GUEST_PAUSED Add new ioctl description to api.txt Documentation/virtual/kvm/api.txt | 12 ++++++++++++ arch/x86/include/asm/kvm_host.h | 2 ++ arch/x86/kvm/x86.c | 20 ++++++++++++++++++++ include/linux/kvm.h | 2 ++ 4 files changed, 36 insertions(+), 0 deletions(-)
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index 7945b0b..0f7dd99 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt@@ -1450,6 +1450,18 @@ is supported; 2 if the processor requires all virtual machines to have an RMA, or 1 if the processor can use an RMA but doesn't require it, because it supports the Virtual RMA (VRMA) facility. +4.64 KVMCLOCK_GUEST_PAUSED + +Capability: basic +Architechtures: Any that implement pvclocks (currently x86 only) +Type: vcpu ioctl +Parameters: None +Returns: 0 on success, -1 on error + +This signals to the host kernel that the specified guest is being paused by +userspace. The host will set a flag in the pvclock structure that is checked +from the soft lockup watchdog. + 5. The kvm_run structure Application code obtains a pointer to the kvm_run structure by
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index b4973f4..beb94c6 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h@@ -672,6 +672,8 @@ int kvm_pv_mmu_op(struct kvm_vcpu *vcpu, unsigned long bytes, gpa_t addr, unsigned long *ret); u8 kvm_get_guest_memory_type(struct kvm_vcpu *vcpu, gfn_t gfn); +int kvm_set_guest_paused(struct kvm_vcpu *vcpu); + extern bool tdp_enabled; u64 vcpu_tsc_khz(struct kvm_vcpu *vcpu);
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index c38efd7..1dab5fd 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c@@ -3295,6 +3295,10 @@ long kvm_arch_vcpu_ioctl(struct file *filp, goto out; } + case KVMCLOCK_GUEST_PAUSED: { + r = kvm_set_guest_paused(vcpu); + break; + } default: r = -EINVAL; }
@@ -6117,6 +6121,22 @@ int kvm_task_switch(struct kvm_vcpu *vcpu, u16 tss_selector, int reason, } EXPORT_SYMBOL_GPL(kvm_task_switch); +/* + * kvm_set_guest_paused() indicates to the guest kernel that it has been + * stopped by the hypervisor. This function will be called from the host only. + * EINVAL is returned when the host attempts to set the flag for a guest that + * does not support pv clocks. + */ +int kvm_set_guest_paused(struct kvm_vcpu *vcpu) +{ + struct pvclock_vcpu_time_info *src = &vcpu->arch.hv_clock; + if (!vcpu->arch.time_page) + return -EINVAL; + src->flags |= PVCLOCK_GUEST_STOPPED; + return 0; +} +EXPORT_SYMBOL_GPL(kvm_set_guest_paused); + int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu, struct kvm_sregs *sregs) {
diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index c3892fc..1d1ddef 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h@@ -762,6 +762,8 @@ struct kvm_clock_data { #define KVM_CREATE_SPAPR_TCE _IOW(KVMIO, 0xa8, struct kvm_create_spapr_tce) /* Available with KVM_CAP_RMA */ #define KVM_ALLOCATE_RMA _IOR(KVMIO, 0xa9, struct kvm_allocate_rma) +/* VM is being stopped by host */ +#define KVMCLOCK_GUEST_PAUSED _IO(KVMIO, 0xaa) #define KVM_DEV_ASSIGN_ENABLE_IOMMU (1 << 0)
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1.7.5.4