Version 2 of the GHCB specification added the advertisement of features
that are supported by the hypervisor. If the hypervisor supports SEV-SNP
then it must set the SEV-SNP features bit to indicate that the base
functionality is supported.
Check that feature bit while establishing the GHCB; if failed, terminate
the guest.
Version 2 of the GHCB specification adds several new Non-Automatic Exits
(NAEs), most of them are optional except the hypervisor feature. Now
that the hypervisor feature NAE is implemented, bump the GHCB maximum
supported protocol version.
While at it, move the GHCB protocol negotiation check from the #VC
exception handler to sev_enable() so that all feature detection happens
before the first #VC exception.
While at it, document why the GHCB page cannot be setup from
load_stage2_idt().
[ bp: Massage commit message. ]
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20220307213356.2797205-13-brijesh.singh@amd.com
The SEV-ES guest calls sev_es_negotiate_protocol() to negotiate the GHCB
protocol version before establishing the GHCB. Cache the negotiated GHCB
version so that it can be used later.
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Venu Busireddy <venu.busireddy@oracle.com>
Link: https://lore.kernel.org/r/20220307213356.2797205-12-brijesh.singh@amd.com
Hyper-V needs to issue the GHCB HV call in order to read/write MSRs in
Isolation VMs. For that, expose sev_es_ghcb_hv_call().
The Hyper-V Isolation VMs are unenlightened guests and run a paravisor
at VMPL0 for communicating. GHCB pages are being allocated and set up
by that paravisor. Linux gets the GHCB page's physical address via
MSR_AMD64_SEV_ES_GHCB from the paravisor and should not change it.
Add a @set_ghcb_msr parameter to sev_es_ghcb_hv_call() to control
whether the function should set the GHCB's address prior to the call or
not and export that function for use by HyperV.
[ bp: - Massage commit message
- add a struct ghcb forward declaration to fix randconfig builds. ]
Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20211025122116.264793-6-ltykernel@gmail.com
The guest and the hypervisor contain separate macros to get and set
the GHCB MSR protocol and NAE event fields. Consolidate the GHCB
protocol definitions and helper macros in one place.
Leave the supported protocol version define in separate files to keep
the guest and hypervisor flexibility to support different GHCB version
in the same release.
There is no functional change intended.
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Joerg Roedel <jroedel@suse.de>
Link: https://lkml.kernel.org/r/20210427111636.1207-3-brijesh.singh@amd.com
SEV-SNP builds upon the SEV-ES functionality while adding new hardware
protection. Version 2 of the GHCB specification adds new NAE events that
are SEV-SNP specific. Rename the sev-es.{ch} to sev.{ch} so that all
SEV* functionality can be consolidated in one place.
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Joerg Roedel <jroedel@suse.de>
Link: https://lkml.kernel.org/r/20210427111636.1207-2-brijesh.singh@amd.com
Brijesh Singh