| Message ID | 20190712011934.29863-2-mdroth@linux.vnet.ibm.com |
|---|---|
| State | New |
| Headers | show |
| Series | spapr: Implement H_TPM_COMM for accessing host TPM device | expand |
On Thu, Jul 11, 2019 at 08:19:33PM -0500, Michael Roth wrote: > For now this only covers hcalls relating to TPM communication since > it's the only one particularly important from a QEMU perspective atm, > but others can be added here where it makes sense. > > The full specification for all hcalls/ucalls will eventually be made > available in the public/OpenPower version of the PAPR specification. > > Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com> Thanks for adding this documentation. Is there a PAPR extension proposal which covers this, which we could cite as the source? > --- > docs/specs/ppc-spapr-uv-hcalls.txt | 74 ++++++++++++++++++++++++++++++ > 1 file changed, 74 insertions(+) > create mode 100644 docs/specs/ppc-spapr-uv-hcalls.txt > > diff --git a/docs/specs/ppc-spapr-uv-hcalls.txt b/docs/specs/ppc-spapr-uv-hcalls.txt > new file mode 100644 > index 0000000000..0278f89190 > --- /dev/null > +++ b/docs/specs/ppc-spapr-uv-hcalls.txt > @@ -0,0 +1,74 @@ > +On PPC64 systems supporting Protected Execution Facility (PEF), system > +memory can be placed in a secured region where only an "ultravisor" > +running in firmware can provide to access it. pseries guests on such > +systems can communicate with the ultravisor (via ultracalls) to switch to a > +secure VM mode (SVM) where the guest's memory is relocated to this secured > +region, making its memory inaccessible to normal processes/guests running on > +the host. > + > +The various ultracalls/hypercalls relating to SVM mode are currently > +only documented internally, but are planned for direct inclusion into the > +public OpenPOWER version of the PAPR specification (LoPAPR/LoPAR). An internal > +ACR has been filed to reserve a hypercall number range specific to this > +use-case to avoid any future conflicts with the internally-maintained PAPR > +specification. This document summarizes some of these details as they relate > +to QEMU. > + > +== hypercalls needed by the ultravisor == > + > +Switching to SVM mode involves a number of hcalls issued by the ultravisor > +to the hypervisor to orchestrate the movement of guest memory to secure > +memory and various other aspects SVM mode. The below documents the hcalls > +relevant to QEMU. > + > +- H_TPM_COMM (0xef10) > + > + For TPM_COMM_OP_EXECUTE operation: > + Send a request to a TPM and receive a response, opening a new TPM session > + if one has not already been opened. > + > + For TPM_COMM_OP_CLOSE_SESSION operation: > + Close the existing TPM session, if any. > + > + Arguments: > + > + r3 : H_TPM_COMM (0xef10) > + r4 : TPM operation, one of: > + TPM_COMM_OP_EXECUTE (0x1) > + TPM_COMM_OP_CLOSE_SESSION (0x2) > + r5 : in_buffer, guest physical address of buffer containing the request > + - Caller may use the same address for both request and response > + r6 : in_size, size of the in buffer, must > + - Must be less than or equal to 4KB > + r7 : out_buffer, guest physical address of buffer to store the response > + - Caller may use the same address for both request and response > + r8 : out_size, size of the out buffer > + - Must be at least 4KB, as this is the maximum request/response size > + supported by most TPM implementations, including the TPM Resource > + Manager in the linux kernel. > + > + Return values: > + > + r3 : H_Success request processed successfully > + H_PARAMETER invalid TPM operation > + H_P2 in_buffer is invalid > + H_P3 in_size is invalid > + H_P4 out_buffer is invalid > + H_P5 out_size is invalid > + H_RESOURCE TPM is unavailable > + r4 : For TPM_COMM_OP_EXECUTE, the size of the response will be stored here > + upon success. > + > + Use-case/notes: > + > + SVM filesystems are encrypted using a symmetric key. This key is then > + wrapped/encrypted using the public key of a trusted system which has the > + private key stored in the system's TPM. An Ultravisor will use this > + hcall to unwrap/unseal the symmetric key using the system's TPM device > + or a TPM Resource Manager associated with the device. > + > + The Ultravisor sets up a separate session key with the TPM in advance > + during host system boot. All sensitive in and out values will be > + encrypted using the session key. Though the hypervisor will see the 'in' > + and 'out' buffers in raw form, any sensitive contents will generally be > + encrypted using this session key.
Quoting David Gibson (2019-07-12 01:40:27) > On Thu, Jul 11, 2019 at 08:19:33PM -0500, Michael Roth wrote: > > For now this only covers hcalls relating to TPM communication since > > it's the only one particularly important from a QEMU perspective atm, > > but others can be added here where it makes sense. > > > > The full specification for all hcalls/ucalls will eventually be made > > available in the public/OpenPower version of the PAPR specification. > > > > Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com> > > Thanks for adding this documentation. Is there a PAPR extension > proposal which covers this, which we could cite as the source? We have an internal document/repo that serves as a catch-all for the Ultravisor related spec changes. We could make that available publically via github and cite it here until it hits the full spec. Would that work? > > > --- > > docs/specs/ppc-spapr-uv-hcalls.txt | 74 ++++++++++++++++++++++++++++++ > > 1 file changed, 74 insertions(+) > > create mode 100644 docs/specs/ppc-spapr-uv-hcalls.txt > > > > diff --git a/docs/specs/ppc-spapr-uv-hcalls.txt b/docs/specs/ppc-spapr-uv-hcalls.txt > > new file mode 100644 > > index 0000000000..0278f89190 > > --- /dev/null > > +++ b/docs/specs/ppc-spapr-uv-hcalls.txt > > @@ -0,0 +1,74 @@ > > +On PPC64 systems supporting Protected Execution Facility (PEF), system > > +memory can be placed in a secured region where only an "ultravisor" > > +running in firmware can provide to access it. pseries guests on such > > +systems can communicate with the ultravisor (via ultracalls) to switch to a > > +secure VM mode (SVM) where the guest's memory is relocated to this secured > > +region, making its memory inaccessible to normal processes/guests running on > > +the host. > > + > > +The various ultracalls/hypercalls relating to SVM mode are currently > > +only documented internally, but are planned for direct inclusion into the > > +public OpenPOWER version of the PAPR specification (LoPAPR/LoPAR). An internal > > +ACR has been filed to reserve a hypercall number range specific to this > > +use-case to avoid any future conflicts with the internally-maintained PAPR > > +specification. This document summarizes some of these details as they relate > > +to QEMU. > > + > > +== hypercalls needed by the ultravisor == > > + > > +Switching to SVM mode involves a number of hcalls issued by the ultravisor > > +to the hypervisor to orchestrate the movement of guest memory to secure > > +memory and various other aspects SVM mode. The below documents the hcalls > > +relevant to QEMU. > > + > > +- H_TPM_COMM (0xef10) > > + > > + For TPM_COMM_OP_EXECUTE operation: > > + Send a request to a TPM and receive a response, opening a new TPM session > > + if one has not already been opened. > > + > > + For TPM_COMM_OP_CLOSE_SESSION operation: > > + Close the existing TPM session, if any. > > + > > + Arguments: > > + > > + r3 : H_TPM_COMM (0xef10) > > + r4 : TPM operation, one of: > > + TPM_COMM_OP_EXECUTE (0x1) > > + TPM_COMM_OP_CLOSE_SESSION (0x2) > > + r5 : in_buffer, guest physical address of buffer containing the request > > + - Caller may use the same address for both request and response > > + r6 : in_size, size of the in buffer, must > > + - Must be less than or equal to 4KB > > + r7 : out_buffer, guest physical address of buffer to store the response > > + - Caller may use the same address for both request and response > > + r8 : out_size, size of the out buffer > > + - Must be at least 4KB, as this is the maximum request/response size > > + supported by most TPM implementations, including the TPM Resource > > + Manager in the linux kernel. > > + > > + Return values: > > + > > + r3 : H_Success request processed successfully > > + H_PARAMETER invalid TPM operation > > + H_P2 in_buffer is invalid > > + H_P3 in_size is invalid > > + H_P4 out_buffer is invalid > > + H_P5 out_size is invalid > > + H_RESOURCE TPM is unavailable > > + r4 : For TPM_COMM_OP_EXECUTE, the size of the response will be stored here > > + upon success. > > + > > + Use-case/notes: > > + > > + SVM filesystems are encrypted using a symmetric key. This key is then > > + wrapped/encrypted using the public key of a trusted system which has the > > + private key stored in the system's TPM. An Ultravisor will use this > > + hcall to unwrap/unseal the symmetric key using the system's TPM device > > + or a TPM Resource Manager associated with the device. > > + > > + The Ultravisor sets up a separate session key with the TPM in advance > > + during host system boot. All sensitive in and out values will be > > + encrypted using the session key. Though the hypervisor will see the 'in' > > + and 'out' buffers in raw form, any sensitive contents will generally be > > + encrypted using this session key. > > -- > David Gibson | I'll have my music baroque, and my code > david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ > | _way_ _around_! > http://www.ozlabs.org/~dgibson
On Fri, Jul 12, 2019 at 10:13:48AM -0500, Michael Roth wrote: > Quoting David Gibson (2019-07-12 01:40:27) > > On Thu, Jul 11, 2019 at 08:19:33PM -0500, Michael Roth wrote: > > > For now this only covers hcalls relating to TPM communication since > > > it's the only one particularly important from a QEMU perspective atm, > > > but others can be added here where it makes sense. > > > > > > The full specification for all hcalls/ucalls will eventually be made > > > available in the public/OpenPower version of the PAPR specification. > > > > > > Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com> > > > > Thanks for adding this documentation. Is there a PAPR extension > > proposal which covers this, which we could cite as the source? > > We have an internal document/repo that serves as a catch-all for the Ultravisor > related spec changes. We could make that available publically via github and > cite it here until it hits the full spec. Would that work? Yes, that sounds good.
Quoting David Gibson (2019-07-14 21:25:55) > On Fri, Jul 12, 2019 at 10:13:48AM -0500, Michael Roth wrote: > > Quoting David Gibson (2019-07-12 01:40:27) > > > On Thu, Jul 11, 2019 at 08:19:33PM -0500, Michael Roth wrote: > > > > For now this only covers hcalls relating to TPM communication since > > > > it's the only one particularly important from a QEMU perspective atm, > > > > but others can be added here where it makes sense. > > > > > > > > The full specification for all hcalls/ucalls will eventually be made > > > > available in the public/OpenPower version of the PAPR specification. > > > > > > > > Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com> > > > > > > Thanks for adding this documentation. Is there a PAPR extension > > > proposal which covers this, which we could cite as the source? > > > > We have an internal document/repo that serves as a catch-all for the Ultravisor > > related spec changes. We could make that available publically via github and > > cite it here until it hits the full spec. Would that work? > > Yes, that sounds good. Ok, we're working on getting that posted externally. If it's not up in time for next submission I will send a follow-up patch to add a reference. > > -- > David Gibson | I'll have my music baroque, and my code > david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ > | _way_ _around_! > http://www.ozlabs.org/~dgibson
diff --git a/docs/specs/ppc-spapr-uv-hcalls.txt b/docs/specs/ppc-spapr-uv-hcalls.txt new file mode 100644 index 0000000000..0278f89190 --- /dev/null +++ b/docs/specs/ppc-spapr-uv-hcalls.txt @@ -0,0 +1,74 @@ +On PPC64 systems supporting Protected Execution Facility (PEF), system +memory can be placed in a secured region where only an "ultravisor" +running in firmware can provide to access it. pseries guests on such +systems can communicate with the ultravisor (via ultracalls) to switch to a +secure VM mode (SVM) where the guest's memory is relocated to this secured +region, making its memory inaccessible to normal processes/guests running on +the host. + +The various ultracalls/hypercalls relating to SVM mode are currently +only documented internally, but are planned for direct inclusion into the +public OpenPOWER version of the PAPR specification (LoPAPR/LoPAR). An internal +ACR has been filed to reserve a hypercall number range specific to this +use-case to avoid any future conflicts with the internally-maintained PAPR +specification. This document summarizes some of these details as they relate +to QEMU. + +== hypercalls needed by the ultravisor == + +Switching to SVM mode involves a number of hcalls issued by the ultravisor +to the hypervisor to orchestrate the movement of guest memory to secure +memory and various other aspects SVM mode. The below documents the hcalls +relevant to QEMU. + +- H_TPM_COMM (0xef10) + + For TPM_COMM_OP_EXECUTE operation: + Send a request to a TPM and receive a response, opening a new TPM session + if one has not already been opened. + + For TPM_COMM_OP_CLOSE_SESSION operation: + Close the existing TPM session, if any. + + Arguments: + + r3 : H_TPM_COMM (0xef10) + r4 : TPM operation, one of: + TPM_COMM_OP_EXECUTE (0x1) + TPM_COMM_OP_CLOSE_SESSION (0x2) + r5 : in_buffer, guest physical address of buffer containing the request + - Caller may use the same address for both request and response + r6 : in_size, size of the in buffer, must + - Must be less than or equal to 4KB + r7 : out_buffer, guest physical address of buffer to store the response + - Caller may use the same address for both request and response + r8 : out_size, size of the out buffer + - Must be at least 4KB, as this is the maximum request/response size + supported by most TPM implementations, including the TPM Resource + Manager in the linux kernel. + + Return values: + + r3 : H_Success request processed successfully + H_PARAMETER invalid TPM operation + H_P2 in_buffer is invalid + H_P3 in_size is invalid + H_P4 out_buffer is invalid + H_P5 out_size is invalid + H_RESOURCE TPM is unavailable + r4 : For TPM_COMM_OP_EXECUTE, the size of the response will be stored here + upon success. + + Use-case/notes: + + SVM filesystems are encrypted using a symmetric key. This key is then + wrapped/encrypted using the public key of a trusted system which has the + private key stored in the system's TPM. An Ultravisor will use this + hcall to unwrap/unseal the symmetric key using the system's TPM device + or a TPM Resource Manager associated with the device. + + The Ultravisor sets up a separate session key with the TPM in advance + during host system boot. All sensitive in and out values will be + encrypted using the session key. Though the hypervisor will see the 'in' + and 'out' buffers in raw form, any sensitive contents will generally be + encrypted using this session key.
For now this only covers hcalls relating to TPM communication since it's the only one particularly important from a QEMU perspective atm, but others can be added here where it makes sense. The full specification for all hcalls/ucalls will eventually be made available in the public/OpenPower version of the PAPR specification. Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com> --- docs/specs/ppc-spapr-uv-hcalls.txt | 74 ++++++++++++++++++++++++++++++ 1 file changed, 74 insertions(+) create mode 100644 docs/specs/ppc-spapr-uv-hcalls.txt