| Message ID | 20200923185757.1806-1-sean.j.christopherson@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: Enable hardware before doing arch VM initialization | expand |
On 23.09.20 20:57, Sean Christopherson wrote: > Swap the order of hardware_enable_all() and kvm_arch_init_vm() to > accommodate Intel's Trust Domain Extension (TDX), which needs VMX to be > fully enabled during VM init in order to make SEAMCALLs. > > This also provides consistent ordering between kvm_create_vm() and > kvm_destroy_vm() with respect to calling kvm_arch_destroy_vm() and > hardware_disable_all(). > > Cc: Marc Zyngier <maz@kernel.org> > Cc: James Morse <james.morse@arm.com> > Cc: Julien Thierry <julien.thierry.kdev@gmail.com> > Cc: Suzuki K Poulose <suzuki.poulose@arm.com> > Cc: linux-arm-kernel@lists.infradead.org > Cc: Huacai Chen <chenhc@lemote.com> > Cc: Aleksandar Markovic <aleksandar.qemu.devel@gmail.com> > Cc: linux-mips@vger.kernel.org > Cc: Paul Mackerras <paulus@ozlabs.org> > Cc: kvm-ppc@vger.kernel.org > Cc: Christian Borntraeger <borntraeger@de.ibm.com> > Cc: Janosch Frank <frankja@linux.ibm.com> > Cc: David Hildenbrand <david@redhat.com> > Cc: Cornelia Huck <cohuck@redhat.com> > Cc: Claudio Imbrenda <imbrenda@linux.ibm.com> > Cc: Vitaly Kuznetsov <vkuznets@redhat.com> > Cc: Wanpeng Li <wanpengli@tencent.com> > Cc: Jim Mattson <jmattson@google.com> > Cc: Joerg Roedel <joro@8bytes.org> > Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> > --- > > Obviously not required until the TDX series comes along, but IMO KVM > should be consistent with respect to enabling and disabling virt support > in hardware. > > Tested only on Intel hardware. Unless I missed something, this only > affects x86, Arm and MIPS as hardware enabling is a nop for s390 and PPC. Yes, looks fine from an s390 perspective. Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Hi, Sean, On Thu, Sep 24, 2020 at 3:00 AM Sean Christopherson <sean.j.christopherson@intel.com> wrote: > > Swap the order of hardware_enable_all() and kvm_arch_init_vm() to > accommodate Intel's Trust Domain Extension (TDX), which needs VMX to be > fully enabled during VM init in order to make SEAMCALLs. > > This also provides consistent ordering between kvm_create_vm() and > kvm_destroy_vm() with respect to calling kvm_arch_destroy_vm() and > hardware_disable_all(). Do you means that hardware_enable_all() enable VMX, kvm_arch_init_vm() enable TDX, and TDX depends on VMX enabled at first? If so, can TDX be also enabled at hardware_enable_all()? The swapping seems not affect MIPS, but I observed a fact: kvm_arch_hardware_enable() not only be called at hardware_enable_all(), but also be called at kvm_starting_cpu(). Even if you swap the order, new starting CPUs are not enabled VMX before kvm_arch_init_vm(). (Maybe I am wrong because I'm not familiar with VMX/TDX). Huacai > > Cc: Marc Zyngier <maz@kernel.org> > Cc: James Morse <james.morse@arm.com> > Cc: Julien Thierry <julien.thierry.kdev@gmail.com> > Cc: Suzuki K Poulose <suzuki.poulose@arm.com> > Cc: linux-arm-kernel@lists.infradead.org > Cc: Huacai Chen <chenhc@lemote.com> > Cc: Aleksandar Markovic <aleksandar.qemu.devel@gmail.com> > Cc: linux-mips@vger.kernel.org > Cc: Paul Mackerras <paulus@ozlabs.org> > Cc: kvm-ppc@vger.kernel.org > Cc: Christian Borntraeger <borntraeger@de.ibm.com> > Cc: Janosch Frank <frankja@linux.ibm.com> > Cc: David Hildenbrand <david@redhat.com> > Cc: Cornelia Huck <cohuck@redhat.com> > Cc: Claudio Imbrenda <imbrenda@linux.ibm.com> > Cc: Vitaly Kuznetsov <vkuznets@redhat.com> > Cc: Wanpeng Li <wanpengli@tencent.com> > Cc: Jim Mattson <jmattson@google.com> > Cc: Joerg Roedel <joro@8bytes.org> > Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> > --- > > Obviously not required until the TDX series comes along, but IMO KVM > should be consistent with respect to enabling and disabling virt support > in hardware. > > Tested only on Intel hardware. Unless I missed something, this only > affects x86, Arm and MIPS as hardware enabling is a nop for s390 and PPC. > Arm looks safe (based on my mostly clueless reading of the code), but I > have no idea if this will cause problem for MIPS, which is doing all kinds > of things in hardware_enable() that I don't pretend to fully understand. > > virt/kvm/kvm_main.c | 16 ++++++++-------- > 1 file changed, 8 insertions(+), 8 deletions(-) > > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c > index cf88233b819a..58fa19bcfc90 100644 > --- a/virt/kvm/kvm_main.c > +++ b/virt/kvm/kvm_main.c > @@ -766,7 +766,7 @@ static struct kvm *kvm_create_vm(unsigned long type) > struct kvm_memslots *slots = kvm_alloc_memslots(); > > if (!slots) > - goto out_err_no_arch_destroy_vm; > + goto out_err_no_disable; > /* Generations must be different for each address space. */ > slots->generation = i; > rcu_assign_pointer(kvm->memslots[i], slots); > @@ -776,19 +776,19 @@ static struct kvm *kvm_create_vm(unsigned long type) > rcu_assign_pointer(kvm->buses[i], > kzalloc(sizeof(struct kvm_io_bus), GFP_KERNEL_ACCOUNT)); > if (!kvm->buses[i]) > - goto out_err_no_arch_destroy_vm; > + goto out_err_no_disable; > } > > kvm->max_halt_poll_ns = halt_poll_ns; > > - r = kvm_arch_init_vm(kvm, type); > - if (r) > - goto out_err_no_arch_destroy_vm; > - > r = hardware_enable_all(); > if (r) > goto out_err_no_disable; > > + r = kvm_arch_init_vm(kvm, type); > + if (r) > + goto out_err_no_arch_destroy_vm; > + > #ifdef CONFIG_HAVE_KVM_IRQFD > INIT_HLIST_HEAD(&kvm->irq_ack_notifier_list); > #endif > @@ -815,10 +815,10 @@ static struct kvm *kvm_create_vm(unsigned long type) > mmu_notifier_unregister(&kvm->mmu_notifier, current->mm); > #endif > out_err_no_mmu_notifier: > - hardware_disable_all(); > -out_err_no_disable: > kvm_arch_destroy_vm(kvm); > out_err_no_arch_destroy_vm: > + hardware_disable_all(); > +out_err_no_disable: > WARN_ON_ONCE(!refcount_dec_and_test(&kvm->users_count)); > for (i = 0; i < KVM_NR_BUSES; i++) > kfree(kvm_get_bus(kvm, i)); > -- > 2.28.0 >
On 24/09/20 08:31, Huacai Chen wrote: > Hi, Sean, > > On Thu, Sep 24, 2020 at 3:00 AM Sean Christopherson > <sean.j.christopherson@intel.com> wrote: >> >> Swap the order of hardware_enable_all() and kvm_arch_init_vm() to >> accommodate Intel's Trust Domain Extension (TDX), which needs VMX to be >> fully enabled during VM init in order to make SEAMCALLs. >> >> This also provides consistent ordering between kvm_create_vm() and >> kvm_destroy_vm() with respect to calling kvm_arch_destroy_vm() and >> hardware_disable_all(). > Do you means that hardware_enable_all() enable VMX, kvm_arch_init_vm() > enable TDX, and TDX depends on VMX enabled at first? If so, can TDX be > also enabled at hardware_enable_all()? kvm_arch_init_vm() enables TDX *for the VM*, and to do that it needs VMX instructions (specifically SEAMCALL, which is a hypervisor->"ultravisor" call). Because that action is VM-specific it cannot be done in hardware_enable_all(). Paolo > The swapping seems not affect MIPS, but I observed a fact: > kvm_arch_hardware_enable() not only be called at > hardware_enable_all(), but also be called at kvm_starting_cpu(). Even > if you swap the order, new starting CPUs are not enabled VMX before > kvm_arch_init_vm(). (Maybe I am wrong because I'm not familiar with > VMX/TDX). > > Huacai >> >> Cc: Marc Zyngier <maz@kernel.org> >> Cc: James Morse <james.morse@arm.com> >> Cc: Julien Thierry <julien.thierry.kdev@gmail.com> >> Cc: Suzuki K Poulose <suzuki.poulose@arm.com> >> Cc: linux-arm-kernel@lists.infradead.org >> Cc: Huacai Chen <chenhc@lemote.com> >> Cc: Aleksandar Markovic <aleksandar.qemu.devel@gmail.com> >> Cc: linux-mips@vger.kernel.org >> Cc: Paul Mackerras <paulus@ozlabs.org> >> Cc: kvm-ppc@vger.kernel.org >> Cc: Christian Borntraeger <borntraeger@de.ibm.com> >> Cc: Janosch Frank <frankja@linux.ibm.com> >> Cc: David Hildenbrand <david@redhat.com> >> Cc: Cornelia Huck <cohuck@redhat.com> >> Cc: Claudio Imbrenda <imbrenda@linux.ibm.com> >> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> >> Cc: Wanpeng Li <wanpengli@tencent.com> >> Cc: Jim Mattson <jmattson@google.com> >> Cc: Joerg Roedel <joro@8bytes.org> >> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> >> --- >> >> Obviously not required until the TDX series comes along, but IMO KVM >> should be consistent with respect to enabling and disabling virt support >> in hardware. >> >> Tested only on Intel hardware. Unless I missed something, this only >> affects x86, Arm and MIPS as hardware enabling is a nop for s390 and PPC. >> Arm looks safe (based on my mostly clueless reading of the code), but I >> have no idea if this will cause problem for MIPS, which is doing all kinds >> of things in hardware_enable() that I don't pretend to fully understand. >> >> virt/kvm/kvm_main.c | 16 ++++++++-------- >> 1 file changed, 8 insertions(+), 8 deletions(-) >> >> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c >> index cf88233b819a..58fa19bcfc90 100644 >> --- a/virt/kvm/kvm_main.c >> +++ b/virt/kvm/kvm_main.c >> @@ -766,7 +766,7 @@ static struct kvm *kvm_create_vm(unsigned long type) >> struct kvm_memslots *slots = kvm_alloc_memslots(); >> >> if (!slots) >> - goto out_err_no_arch_destroy_vm; >> + goto out_err_no_disable; >> /* Generations must be different for each address space. */ >> slots->generation = i; >> rcu_assign_pointer(kvm->memslots[i], slots); >> @@ -776,19 +776,19 @@ static struct kvm *kvm_create_vm(unsigned long type) >> rcu_assign_pointer(kvm->buses[i], >> kzalloc(sizeof(struct kvm_io_bus), GFP_KERNEL_ACCOUNT)); >> if (!kvm->buses[i]) >> - goto out_err_no_arch_destroy_vm; >> + goto out_err_no_disable; >> } >> >> kvm->max_halt_poll_ns = halt_poll_ns; >> >> - r = kvm_arch_init_vm(kvm, type); >> - if (r) >> - goto out_err_no_arch_destroy_vm; >> - >> r = hardware_enable_all(); >> if (r) >> goto out_err_no_disable; >> >> + r = kvm_arch_init_vm(kvm, type); >> + if (r) >> + goto out_err_no_arch_destroy_vm; >> + >> #ifdef CONFIG_HAVE_KVM_IRQFD >> INIT_HLIST_HEAD(&kvm->irq_ack_notifier_list); >> #endif >> @@ -815,10 +815,10 @@ static struct kvm *kvm_create_vm(unsigned long type) >> mmu_notifier_unregister(&kvm->mmu_notifier, current->mm); >> #endif >> out_err_no_mmu_notifier: >> - hardware_disable_all(); >> -out_err_no_disable: >> kvm_arch_destroy_vm(kvm); >> out_err_no_arch_destroy_vm: >> + hardware_disable_all(); >> +out_err_no_disable: >> WARN_ON_ONCE(!refcount_dec_and_test(&kvm->users_count)); >> for (i = 0; i < KVM_NR_BUSES; i++) >> kfree(kvm_get_bus(kvm, i)); >> -- >> 2.28.0 >> >
Hi, Paolo, On Thu, Sep 24, 2020 at 2:50 PM Paolo Bonzini <pbonzini@redhat.com> wrote: > > On 24/09/20 08:31, Huacai Chen wrote: > > Hi, Sean, > > > > On Thu, Sep 24, 2020 at 3:00 AM Sean Christopherson > > <sean.j.christopherson@intel.com> wrote: > >> > >> Swap the order of hardware_enable_all() and kvm_arch_init_vm() to > >> accommodate Intel's Trust Domain Extension (TDX), which needs VMX to be > >> fully enabled during VM init in order to make SEAMCALLs. > >> > >> This also provides consistent ordering between kvm_create_vm() and > >> kvm_destroy_vm() with respect to calling kvm_arch_destroy_vm() and > >> hardware_disable_all(). > > Do you means that hardware_enable_all() enable VMX, kvm_arch_init_vm() > > enable TDX, and TDX depends on VMX enabled at first? If so, can TDX be > > also enabled at hardware_enable_all()? > > kvm_arch_init_vm() enables TDX *for the VM*, and to do that it needs VMX > instructions (specifically SEAMCALL, which is a hypervisor->"ultravisor" > call). Because that action is VM-specific it cannot be done in > hardware_enable_all(). > > Paolo OK, I know. Reviewed-by: Huacai Chen <chenhc@lemote.com> > > > The swapping seems not affect MIPS, but I observed a fact: > > kvm_arch_hardware_enable() not only be called at > > hardware_enable_all(), but also be called at kvm_starting_cpu(). Even > > if you swap the order, new starting CPUs are not enabled VMX before > > kvm_arch_init_vm(). (Maybe I am wrong because I'm not familiar with > > VMX/TDX). > > > > Huacai > >> > >> Cc: Marc Zyngier <maz@kernel.org> > >> Cc: James Morse <james.morse@arm.com> > >> Cc: Julien Thierry <julien.thierry.kdev@gmail.com> > >> Cc: Suzuki K Poulose <suzuki.poulose@arm.com> > >> Cc: linux-arm-kernel@lists.infradead.org > >> Cc: Huacai Chen <chenhc@lemote.com> > >> Cc: Aleksandar Markovic <aleksandar.qemu.devel@gmail.com> > >> Cc: linux-mips@vger.kernel.org > >> Cc: Paul Mackerras <paulus@ozlabs.org> > >> Cc: kvm-ppc@vger.kernel.org > >> Cc: Christian Borntraeger <borntraeger@de.ibm.com> > >> Cc: Janosch Frank <frankja@linux.ibm.com> > >> Cc: David Hildenbrand <david@redhat.com> > >> Cc: Cornelia Huck <cohuck@redhat.com> > >> Cc: Claudio Imbrenda <imbrenda@linux.ibm.com> > >> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> > >> Cc: Wanpeng Li <wanpengli@tencent.com> > >> Cc: Jim Mattson <jmattson@google.com> > >> Cc: Joerg Roedel <joro@8bytes.org> > >> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> > >> --- > >> > >> Obviously not required until the TDX series comes along, but IMO KVM > >> should be consistent with respect to enabling and disabling virt support > >> in hardware. > >> > >> Tested only on Intel hardware. Unless I missed something, this only > >> affects x86, Arm and MIPS as hardware enabling is a nop for s390 and PPC. > >> Arm looks safe (based on my mostly clueless reading of the code), but I > >> have no idea if this will cause problem for MIPS, which is doing all kinds > >> of things in hardware_enable() that I don't pretend to fully understand. > >> > >> virt/kvm/kvm_main.c | 16 ++++++++-------- > >> 1 file changed, 8 insertions(+), 8 deletions(-) > >> > >> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c > >> index cf88233b819a..58fa19bcfc90 100644 > >> --- a/virt/kvm/kvm_main.c > >> +++ b/virt/kvm/kvm_main.c > >> @@ -766,7 +766,7 @@ static struct kvm *kvm_create_vm(unsigned long type) > >> struct kvm_memslots *slots = kvm_alloc_memslots(); > >> > >> if (!slots) > >> - goto out_err_no_arch_destroy_vm; > >> + goto out_err_no_disable; > >> /* Generations must be different for each address space. */ > >> slots->generation = i; > >> rcu_assign_pointer(kvm->memslots[i], slots); > >> @@ -776,19 +776,19 @@ static struct kvm *kvm_create_vm(unsigned long type) > >> rcu_assign_pointer(kvm->buses[i], > >> kzalloc(sizeof(struct kvm_io_bus), GFP_KERNEL_ACCOUNT)); > >> if (!kvm->buses[i]) > >> - goto out_err_no_arch_destroy_vm; > >> + goto out_err_no_disable; > >> } > >> > >> kvm->max_halt_poll_ns = halt_poll_ns; > >> > >> - r = kvm_arch_init_vm(kvm, type); > >> - if (r) > >> - goto out_err_no_arch_destroy_vm; > >> - > >> r = hardware_enable_all(); > >> if (r) > >> goto out_err_no_disable; > >> > >> + r = kvm_arch_init_vm(kvm, type); > >> + if (r) > >> + goto out_err_no_arch_destroy_vm; > >> + > >> #ifdef CONFIG_HAVE_KVM_IRQFD > >> INIT_HLIST_HEAD(&kvm->irq_ack_notifier_list); > >> #endif > >> @@ -815,10 +815,10 @@ static struct kvm *kvm_create_vm(unsigned long type) > >> mmu_notifier_unregister(&kvm->mmu_notifier, current->mm); > >> #endif > >> out_err_no_mmu_notifier: > >> - hardware_disable_all(); > >> -out_err_no_disable: > >> kvm_arch_destroy_vm(kvm); > >> out_err_no_arch_destroy_vm: > >> + hardware_disable_all(); > >> +out_err_no_disable: > >> WARN_ON_ONCE(!refcount_dec_and_test(&kvm->users_count)); > >> for (i = 0; i < KVM_NR_BUSES; i++) > >> kfree(kvm_get_bus(kvm, i)); > >> -- > >> 2.28.0 > >> > > >
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index cf88233b819a..58fa19bcfc90 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -766,7 +766,7 @@ static struct kvm *kvm_create_vm(unsigned long type) struct kvm_memslots *slots = kvm_alloc_memslots(); if (!slots) - goto out_err_no_arch_destroy_vm; + goto out_err_no_disable; /* Generations must be different for each address space. */ slots->generation = i; rcu_assign_pointer(kvm->memslots[i], slots); @@ -776,19 +776,19 @@ static struct kvm *kvm_create_vm(unsigned long type) rcu_assign_pointer(kvm->buses[i], kzalloc(sizeof(struct kvm_io_bus), GFP_KERNEL_ACCOUNT)); if (!kvm->buses[i]) - goto out_err_no_arch_destroy_vm; + goto out_err_no_disable; } kvm->max_halt_poll_ns = halt_poll_ns; - r = kvm_arch_init_vm(kvm, type); - if (r) - goto out_err_no_arch_destroy_vm; - r = hardware_enable_all(); if (r) goto out_err_no_disable; + r = kvm_arch_init_vm(kvm, type); + if (r) + goto out_err_no_arch_destroy_vm; + #ifdef CONFIG_HAVE_KVM_IRQFD INIT_HLIST_HEAD(&kvm->irq_ack_notifier_list); #endif @@ -815,10 +815,10 @@ static struct kvm *kvm_create_vm(unsigned long type) mmu_notifier_unregister(&kvm->mmu_notifier, current->mm); #endif out_err_no_mmu_notifier: - hardware_disable_all(); -out_err_no_disable: kvm_arch_destroy_vm(kvm); out_err_no_arch_destroy_vm: + hardware_disable_all(); +out_err_no_disable: WARN_ON_ONCE(!refcount_dec_and_test(&kvm->users_count)); for (i = 0; i < KVM_NR_BUSES; i++) kfree(kvm_get_bus(kvm, i));
Swap the order of hardware_enable_all() and kvm_arch_init_vm() to accommodate Intel's Trust Domain Extension (TDX), which needs VMX to be fully enabled during VM init in order to make SEAMCALLs. This also provides consistent ordering between kvm_create_vm() and kvm_destroy_vm() with respect to calling kvm_arch_destroy_vm() and hardware_disable_all(). Cc: Marc Zyngier <maz@kernel.org> Cc: James Morse <james.morse@arm.com> Cc: Julien Thierry <julien.thierry.kdev@gmail.com> Cc: Suzuki K Poulose <suzuki.poulose@arm.com> Cc: linux-arm-kernel@lists.infradead.org Cc: Huacai Chen <chenhc@lemote.com> Cc: Aleksandar Markovic <aleksandar.qemu.devel@gmail.com> Cc: linux-mips@vger.kernel.org Cc: Paul Mackerras <paulus@ozlabs.org> Cc: kvm-ppc@vger.kernel.org Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Janosch Frank <frankja@linux.ibm.com> Cc: David Hildenbrand <david@redhat.com> Cc: Cornelia Huck <cohuck@redhat.com> Cc: Claudio Imbrenda <imbrenda@linux.ibm.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Wanpeng Li <wanpengli@tencent.com> Cc: Jim Mattson <jmattson@google.com> Cc: Joerg Roedel <joro@8bytes.org> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> --- Obviously not required until the TDX series comes along, but IMO KVM should be consistent with respect to enabling and disabling virt support in hardware. Tested only on Intel hardware. Unless I missed something, this only affects x86, Arm and MIPS as hardware enabling is a nop for s390 and PPC. Arm looks safe (based on my mostly clueless reading of the code), but I have no idea if this will cause problem for MIPS, which is doing all kinds of things in hardware_enable() that I don't pretend to fully understand. virt/kvm/kvm_main.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-)