On 11/01/2009 01:56 PM, Gleb Natapov wrote:
Add hypercall that allows guest and host to setup per cpu shared
memory.
Better to set this up as an MSR (with bit zero enabling, bits 1-5
features, and 64-byte alignment). This allows auto-reset on INIT and
live migration using the existing MSR save/restore infrastructure.
arch/x86/include/asm/kvm_host.h | 3 +
arch/x86/include/asm/kvm_para.h | 11 +++++
arch/x86/kernel/kvm.c | 82 +++++++++++++++++++++++++++++++++++++++
arch/x86/kernel/setup.c | 1 +
arch/x86/kernel/smpboot.c | 3 +
arch/x86/kvm/x86.c | 70 +++++++++++++++++++++++++++++++++
include/linux/kvm.h | 1 +
include/linux/kvm_para.h | 4 ++
8 files changed, 175 insertions(+), 0 deletions(-)
Please separate into guest and host patches.
+#define KVM_PV_SHM_VERSION 1
versions = bad, feature bits = good
+
+#define KVM_PV_SHM_FEATURES_ASYNC_PF (1<< 0)
+
+struct kvm_vcpu_pv_shm {
+ __u64 features;
+ __u64 reason;
+ __u64 param;
+};
+
Some documentation for this?
Also, the name should reflect the pv pagefault use. For other uses we
can register other areas.
#define MMU_QUEUE_SIZE 1024
@@ -37,6 +41,7 @@ struct kvm_para_state {
};
static DEFINE_PER_CPU(struct kvm_para_state, para_state);
+static DEFINE_PER_CPU(struct kvm_vcpu_pv_shm *, kvm_vcpu_pv_shm);
Easier to put the entire structure here, not a pointer.
+
+static int kvm_pv_reboot_notify(struct notifier_block *nb,
+ unsigned long code, void *unused)
+{
+ if (code == SYS_RESTART)
+ on_each_cpu(kvm_pv_unregister_shm, NULL, 1);
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block kvm_pv_reboot_nb = {
+ .notifier_call = kvm_pv_reboot_notify,
+};
Is this called on kexec, or do we need another hook?
+static int kvm_pv_setup_shm(struct kvm_vcpu *vcpu, unsigned long gpa,
+ unsigned long size, unsigned long version,
+ unsigned long *ret)
+{
+ addr = gfn_to_hva(vcpu->kvm, gfn);
+ if (kvm_is_error_hva(addr))
+ return -EFAULT;
+
+ /* pin page with pv shared memory */
+ down_read(&mm->mmap_sem);
+ r = get_user_pages(current, mm, addr, 1, 1, 0,&vcpu->arch.pv_shm_page,
+ NULL);
+ up_read(&mm->mmap_sem);
This fails if the memory area straddles a page boundary. Aligning would
solve this. I prefer using put_user() though than a permanent
get_user_pages().
--
error compiling committee.c: too many arguments to function
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