When SEV-ES is enabled, it is not possible modify the guests register
state after it has been initially created, encrypted and measured.
Normally, an INIT-SIPI-SIPI request is used to boot the AP. However, the
hypervisor cannot emulate this because it cannot update the AP register
state. For the very first boot by an AP, the reset vector CS segment
value and the EIP value must be programmed before the register has been
encrypted and measured. Search the guest firmware for the guest for a
specific GUID that tells Qemu the value of the reset vector to use.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Marcel Apfelbaum <marcel.apfelbaum@gmail.com>
Cc: Richard Henderson <richard.henderson@linaro.org>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <22db2bfb4d6551aed661a9ae95b4fdbef613ca21.1611682609.git.thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
OVMF is developing a mechanism for depositing a GUIDed table just
below the known location of the reset vector. The table goes
backwards in memory so all entries are of the form
<data>|len|<GUID>
Where <data> is arbtrary size and type, <len> is a uint16_t and
describes the entire length of the entry from the beginning of the
data to the end of the guid.
The foot of the table is of this form and <len> for this case
describes the entire size of the table. The table foot GUID is
defined by OVMF as 96b582de-1fb2-45f7-baea-a366c55a082d and if the
table is present this GUID is just below the reset vector, 48 bytes
before the end of the firmware file.
Add a parser for the ovmf reset block which takes a copy of the block,
if the table foot guid is found, minus the footer and a function for
later traversal to return the data area of any specified GUIDs.
Signed-off-by: James Bottomley <jejb@linux.ibm.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20210204193939.16617-2-jejb@linux.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This allows failures to be reported richly and idiomatically.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Currently the "memory-encryption" property is only looked at once we
get to kvm_init(). Although protection of guest memory from the
hypervisor isn't something that could really ever work with TCG, it's
not conceptually tied to the KVM accelerator.
In addition, the way the string property is resolved to an object is
almost identical to how a QOM link property is handled.
So, create a new "confidential-guest-support" link property which sets
this QOM interface link directly in the machine. For compatibility we
keep the "memory-encryption" property, but now implemented in terms of
the new property.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
When AMD's SEV memory encryption is in use, flash memory banks (which are
initialed by pc_system_flash_map()) need to be encrypted with the guest's
key, so that the guest can read them.
That's abstracted via the kvm_memcrypt_encrypt_data() callback in the KVM
state.. except, that it doesn't really abstract much at all.
For starters, the only call site is in code specific to the 'pc'
family of machine types, so it's obviously specific to those and to
x86 to begin with. But it makes a bunch of further assumptions that
need not be true about an arbitrary confidential guest system based on
memory encryption, let alone one based on other mechanisms:
* it assumes that the flash memory is defined to be encrypted with the
guest key, rather than being shared with hypervisor
* it assumes that that hypervisor has some mechanism to encrypt data into
the guest, even though it can't decrypt it out, since that's the whole
point
* the interface assumes that this encrypt can be done in place, which
implies that the hypervisor can write into a confidential guests's
memory, even if what it writes isn't meaningful
So really, this "abstraction" is actually pretty specific to the way SEV
works. So, this patch removes it and instead has the PC flash
initialization code call into a SEV specific callback.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
AMD SEV allows a guest owner to inject a secret blob
into the memory of a virtual machine. The secret is
encrypted with the SEV Transport Encryption Key and
integrity is guaranteed with the Transport Integrity
Key. Although QEMU facilitates the injection of the
launch secret, it cannot access the secret.
Signed-off-by: Tobin Feldman-Fitzthum <tobin@linux.ibm.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Brijesh Singh <brijesh.singh@amd.com>
Message-Id: <20201027170303.47550-1-tobin@linux.ibm.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Inorder to integerate the Secure Encryption Virtualization (SEV) support
add few high-level memory encryption APIs which can be used for encrypting
the guest memory region.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: kvm@vger.kernel.org
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Split from a patch by Brijesh Singh (brijesh.singh@amd.com).
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
