On Wed, Nov 15, 2023 at 02:49:56PM +0800,
Yuan Yao <yuan.yao@xxxxxxxxxxxxxxx> wrote:
> On Tue, Nov 07, 2023 at 06:56:37AM -0800, isaku.yamahata@xxxxxxxxx wrote:
> > From: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
> >
> > For vcpu migration, in the case of VMX, VMCS is flushed on the source pcpu,
> > and load it on the target pcpu. There are corresponding TDX SEAMCALL APIs,
> > call them on vcpu migration. The logic is mostly same as VMX except the
> > TDX SEAMCALLs are used.
> >
> > When shutting down the machine, (VMX or TDX) vcpus needs to be shutdown on
> > each pcpu. Do the similar for TDX with TDX SEAMCALL APIs.
> >
> > Signed-off-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
> > ---
> > arch/x86/kvm/vmx/main.c | 32 ++++++-
> > arch/x86/kvm/vmx/tdx.c | 190 ++++++++++++++++++++++++++++++++++++-
> > arch/x86/kvm/vmx/tdx.h | 2 +
> > arch/x86/kvm/vmx/x86_ops.h | 4 +
> > 4 files changed, 221 insertions(+), 7 deletions(-)
> >
> > diff --git a/arch/x86/kvm/vmx/main.c b/arch/x86/kvm/vmx/main.c
> > index e7c570686736..8b109d0fe764 100644
> > --- a/arch/x86/kvm/vmx/main.c
> > +++ b/arch/x86/kvm/vmx/main.c
> > @@ -44,6 +44,14 @@ static int vt_hardware_enable(void)
> > return ret;
> > }
> >
> ......
> > -void tdx_mmu_release_hkid(struct kvm *kvm)
> > +static int __tdx_mmu_release_hkid(struct kvm *kvm)
> > {
> > bool packages_allocated, targets_allocated;
> > struct kvm_tdx *kvm_tdx = to_kvm_tdx(kvm);
> > cpumask_var_t packages, targets;
> > + struct kvm_vcpu *vcpu;
> > + unsigned long j;
> > + int i, ret = 0;
> > u64 err;
> > - int i;
> >
> > if (!is_hkid_assigned(kvm_tdx))
> > - return;
> > + return 0;
> >
> > if (!is_td_created(kvm_tdx)) {
> > tdx_hkid_free(kvm_tdx);
> > - return;
> > + return 0;
> > }
> >
> > packages_allocated = zalloc_cpumask_var(&packages, GFP_KERNEL);
> > targets_allocated = zalloc_cpumask_var(&targets, GFP_KERNEL);
> > cpus_read_lock();
> >
> > + kvm_for_each_vcpu(j, vcpu, kvm)
> > + tdx_flush_vp_on_cpu(vcpu);
> > +
> > /*
> > * We can destroy multiple the guest TDs simultaneously. Prevent
> > * tdh_phymem_cache_wb from returning TDX_BUSY by serialization.
> > @@ -236,6 +361,19 @@ void tdx_mmu_release_hkid(struct kvm *kvm)
> > */
> > write_lock(&kvm->mmu_lock);
> >
> > + err = tdh_mng_vpflushdone(kvm_tdx->tdr_pa);
> > + if (err == TDX_FLUSHVP_NOT_DONE) {
>
> Not sure IIUC, The __tdx_mmu_release_hkid() is called in MMU release
> callback, which means all threads of the process have dropped mm by
> do_exit() so they won't run kvm code anymore, and tdx_flush_vp_on_cpu()
> is called for each pcpu they run last time, so will this error really
> happen ?
KVM_TDX_RELEASE_VM calls the function too. Maybe this check should be
introduced with the patch for KVM_TDX_RELEASE_VM.
--
Isaku Yamahata <isaku.yamahata@xxxxxxxxxxxxxxx>
