diff mbox series

[RFC,01/37] DOCUMENTATION: protvirt: Protected virtual machine introduction

Message ID 20191024114059.102802-2-frankja@linux.ibm.com
State New, archived
Headers show
Series KVM: s390: Add support for protected VMs | expand

Commit Message

Janosch Frank Oct. 24, 2019, 11:40 a.m. UTC
Introduction to Protected VMs.

Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
---
 Documentation/virtual/kvm/s390-pv.txt | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)
 create mode 100644 Documentation/virtual/kvm/s390-pv.txt

Comments

Christian Borntraeger Nov. 1, 2019, 8:18 a.m. UTC | #1
On 24.10.19 13:40, Janosch Frank wrote:
> Introduction to Protected VMs.
> 
> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
> ---
>  Documentation/virtual/kvm/s390-pv.txt | 23 +++++++++++++++++++++++
>  1 file changed, 23 insertions(+)
>  create mode 100644 Documentation/virtual/kvm/s390-pv.txt
> 
> diff --git a/Documentation/virtual/kvm/s390-pv.txt b/Documentation/virtual/kvm/s390-pv.txt
> new file mode 100644
> index 000000000000..86ed95f36759
> --- /dev/null
> +++ b/Documentation/virtual/kvm/s390-pv.txt
> @@ -0,0 +1,23 @@
> +Ultravisor and Protected VMs
> +===========================
> +
> +Summary:
> +
> +Protected VMs (PVM) are KVM VMs, where KVM can't access the VM's state
> +like guest memory and guest registers anymore. Instead the PVMs are
> +mostly managed by a new entity called Ultravisor (UV), which provides
> +an API, so KVM and the PVM can request management actions.
> +
> +Each guest starts in the non-protected mode and then transitions into
> +protected mode. On transition KVM registers the guest and its VCPUs
> +with the Ultravisor and prepares everything for running it.
> +
> +The Ultravisor will secure and decrypt the guest's boot memory
> +(i.e. kernel/initrd). It will safeguard state changes like VCPU
> +starts/stops and injected interrupts while the guest is running.
> +
> +As access to the guest's state, like the SIE state description is
                     not a native speaker, but do we need a , /here\ ?
> +normally needed to be able to run a VM, some changes have been made in

> +SIE behavior and fields have different meaning for a PVM. SIE exits
> +are minimized as much as possible to improve speed and reduce exposed
> +guest state.
> 

Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>

After review we could merge all documentation patches into one, if we want.
Cornelia Huck Nov. 4, 2019, 2:18 p.m. UTC | #2
On Thu, 24 Oct 2019 07:40:23 -0400
Janosch Frank <frankja@linux.ibm.com> wrote:

> Introduction to Protected VMs.
> 
> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
> ---
>  Documentation/virtual/kvm/s390-pv.txt | 23 +++++++++++++++++++++++
>  1 file changed, 23 insertions(+)
>  create mode 100644 Documentation/virtual/kvm/s390-pv.txt
> 
> diff --git a/Documentation/virtual/kvm/s390-pv.txt b/Documentation/virtual/kvm/s390-pv.txt
> new file mode 100644
> index 000000000000..86ed95f36759
> --- /dev/null
> +++ b/Documentation/virtual/kvm/s390-pv.txt

This should be under /virt/, I think. Also, maybe start out with RST
already for new files?

> @@ -0,0 +1,23 @@
> +Ultravisor and Protected VMs
> +===========================
> +
> +Summary:
> +
> +Protected VMs (PVM) are KVM VMs, where KVM can't access the VM's state
> +like guest memory and guest registers anymore. Instead the PVMs are

s/Instead/Instead,/

> +mostly managed by a new entity called Ultravisor (UV), which provides
> +an API, so KVM and the PVM can request management actions.

Hm...

"The UV provides an API (both for guests and hypervisors), where PVMs
and KVM can request management actions." ?

> +
> +Each guest starts in the non-protected mode and then transitions into

"and then may make a request to transition into protected mode" ?

> +protected mode. On transition KVM registers the guest and its VCPUs
> +with the Ultravisor and prepares everything for running it.
> +
> +The Ultravisor will secure and decrypt the guest's boot memory
> +(i.e. kernel/initrd). It will safeguard state changes like VCPU
> +starts/stops and injected interrupts while the guest is running.
> +
> +As access to the guest's state, like the SIE state description is

"such as the SIE state description," ?

> +normally needed to be able to run a VM, some changes have been made in
> +SIE behavior and fields have different meaning for a PVM. SIE exits
> +are minimized as much as possible to improve speed and reduce exposed
> +guest state.
Janosch Frank Nov. 12, 2019, 2:38 p.m. UTC | #3
On 11/4/19 3:18 PM, Cornelia Huck wrote:
> On Thu, 24 Oct 2019 07:40:23 -0400
> Janosch Frank <frankja@linux.ibm.com> wrote:
> 
>> Introduction to Protected VMs.
>>
>> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
>> ---
>>  Documentation/virtual/kvm/s390-pv.txt | 23 +++++++++++++++++++++++
>>  1 file changed, 23 insertions(+)
>>  create mode 100644 Documentation/virtual/kvm/s390-pv.txt
>>
>> diff --git a/Documentation/virtual/kvm/s390-pv.txt b/Documentation/virtual/kvm/s390-pv.txt
>> new file mode 100644
>> index 000000000000..86ed95f36759
>> --- /dev/null
>> +++ b/Documentation/virtual/kvm/s390-pv.txt
> 
> This should be under /virt/, I think. Also, maybe start out with RST
> already for new files?
> 
>> @@ -0,0 +1,23 @@
>> +Ultravisor and Protected VMs
>> +===========================
>> +
>> +Summary:
>> +
>> +Protected VMs (PVM) are KVM VMs, where KVM can't access the VM's state
>> +like guest memory and guest registers anymore. Instead the PVMs are
> 
> s/Instead/Instead,/

Fixed

> 
>> +mostly managed by a new entity called Ultravisor (UV), which provides
>> +an API, so KVM and the PVM can request management actions.
> 
> Hm...
> 
> "The UV provides an API (both for guests and hypervisors), where PVMs
> and KVM can request management actions." ?

I applied your proposal, but removed the part in the brace, as it is
obvious from the words that follow.

> 
>> +
>> +Each guest starts in the non-protected mode and then transitions into
> 
> "and then may make a request to transition into protected mode" ?

Sure

> 
>> +protected mode. On transition KVM registers the guest and its VCPUs
>> +with the Ultravisor and prepares everything for running it.
>> +
>> +The Ultravisor will secure and decrypt the guest's boot memory
>> +(i.e. kernel/initrd). It will safeguard state changes like VCPU
>> +starts/stops and injected interrupts while the guest is running.
>> +
>> +As access to the guest's state, like the SIE state description is
> 
> "such as the SIE state description," ?
> 
>> +normally needed to be able to run a VM, some changes have been made in
>> +SIE behavior and fields have different meaning for a PVM. SIE exits
>> +are minimized as much as possible to improve speed and reduce exposed
>> +guest state.
>
diff mbox series

Patch

diff --git a/Documentation/virtual/kvm/s390-pv.txt b/Documentation/virtual/kvm/s390-pv.txt
new file mode 100644
index 000000000000..86ed95f36759
--- /dev/null
+++ b/Documentation/virtual/kvm/s390-pv.txt
@@ -0,0 +1,23 @@ 
+Ultravisor and Protected VMs
+===========================
+
+Summary:
+
+Protected VMs (PVM) are KVM VMs, where KVM can't access the VM's state
+like guest memory and guest registers anymore. Instead the PVMs are
+mostly managed by a new entity called Ultravisor (UV), which provides
+an API, so KVM and the PVM can request management actions.
+
+Each guest starts in the non-protected mode and then transitions into
+protected mode. On transition KVM registers the guest and its VCPUs
+with the Ultravisor and prepares everything for running it.
+
+The Ultravisor will secure and decrypt the guest's boot memory
+(i.e. kernel/initrd). It will safeguard state changes like VCPU
+starts/stops and injected interrupts while the guest is running.
+
+As access to the guest's state, like the SIE state description is
+normally needed to be able to run a VM, some changes have been made in
+SIE behavior and fields have different meaning for a PVM. SIE exits
+are minimized as much as possible to improve speed and reduce exposed
+guest state.