These functions are used when the guest wants to grant the hypervisor
access to certain pages.
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190820021326.6884-6-bauerman@linux.ibm.com
Make the Enter-Secure-Mode (ESM) ultravisor call to switch the VM to secure
mode. Pass kernel base address and FDT address so that the Ultravisor is
able to verify the integrity of the VM using information from the ESM blob.
Add "svm=" command line option to turn on switching to secure mode.
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
[ andmike: Generate an RTAS os-term hcall when the ESM ucall fails. ]
Signed-off-by: Michael Anderson <andmike@linux.ibm.com>
[ bauerman: Cleaned up the code a bit. ]
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190820021326.6884-5-bauerman@linux.ibm.com
When an SVM makes an hypercall or incurs some other exception, the
Ultravisor usually forwards (a.k.a. reflects) the exceptions to the
Hypervisor. After processing the exception, Hypervisor uses the
UV_RETURN ultracall to return control back to the SVM.
The expected register state on entry to this ultracall is:
* Non-volatile registers are restored to their original values.
* If returning from an hypercall, register R0 contains the return value
(unlike other ultracalls) and, registers R4 through R12 contain any
output values of the hypercall.
* R3 contains the ultracall number, i.e UV_RETURN.
* If returning with a synthesized interrupt, R2 contains the
synthesized interrupt number.
Thanks to input from Paul Mackerras, Ram Pai and Mike Anderson.
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Claudio Carvalho <cclaudio@linux.ibm.com>
Acked-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190822034838.27876-8-cclaudio@linux.ibm.com
When Ultravisor (UV) is enabled, the partition table is stored in secure
memory and can only be accessed via the UV. The Hypervisor (HV) however
maintains a copy of the partition table in normal memory to allow Nest MMU
translations to occur (for normal VMs). The HV copy includes partition
table entries (PATE)s for secure VMs which would currently be unused
(Nest MMU translations cannot access secure memory) but they would be
needed as we add functionality.
This patch adds the UV_WRITE_PATE ucall which is used to update the PATE
for a VM (both normal and secure) when Ultravisor is enabled.
Signed-off-by: Michael Anderson <andmike@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
[ cclaudio: Write the PATE in HV's table before doing that in UV's ]
Signed-off-by: Claudio Carvalho <cclaudio@linux.ibm.com>
Reviewed-by: Ryan Grimm <grimm@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190822034838.27876-5-cclaudio@linux.ibm.com
The ultracalls (ucalls for short) allow the Secure Virtual Machines
(SVM)s and hypervisor to request services from the ultravisor such as
accessing a register or memory region that can only be accessed when
running in ultravisor-privileged mode.
This patch adds the ucall_norets() ultravisor call handler.
The specific service needed from an ucall is specified in register
R3 (the first parameter to the ucall). Other parameters to the
ucall, if any, are specified in registers R4 through R12.
Return value of all ucalls is in register R3. Other output values
from the ucall, if any, are returned in registers R4 through R12.
Each ucall returns specific error codes, applicable in the context
of the ucall. However, like with the PowerPC Architecture Platform
Reference (PAPR), if no specific error code is defined for a particular
situation, then the ucall will fallback to an erroneous
parameter-position based code. i.e U_PARAMETER, U_P2, U_P3 etc depending
on the ucall parameter that may have caused the error.
Every host kernel (powernv) needs to be able to do ucalls in case it
ends up being run in a machine with ultravisor enabled. Otherwise, the
kernel may crash early in boot trying to access ultravisor resources,
for instance, trying to set the partition table entry 0. Secure guests
also need to be able to do ucalls and its kernel may not have
CONFIG_PPC_POWERNV=y. For that reason, the ucall.S file is placed under
arch/powerpc/kernel.
If ultravisor is not enabled, the ucalls will be redirected to the
hypervisor which must handle/fail the call.
Thanks to inputs from Ram Pai and Michael Anderson.
Signed-off-by: Claudio Carvalho <cclaudio@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190822034838.27876-3-cclaudio@linux.ibm.com
