Commit Graph

19 Commits

Author SHA1 Message Date
Anthony PERARD b37cfdd280 OvmfPkg/XenPlatformPei: Relocate shared_info page mapping
Unfortunately, Xen isn't ready to deal with mapping at the top of the
physical address space, so we relocate the mapping after the LAPIC
location.

See this thread about the issue with the mapping:
- https://lore.kernel.org/xen-devel/f8c4151a-6dac-d87c-ef46-eb35ada07bd9@suse.com/

The PhysicalAddressIdentityMapping() call isn't going to do anything
anymore since everything under 4GB is already mapped, but there is no
need to remove the call.

Cc: Jan Beulich <JBeulich@suse.com>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Message-Id: <20210628132337.46345-1-anthony.perard@citrix.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
[lersek@redhat.com: replace "CC:" with "Cc:", to pacify PatchCheck.py]
2021-06-29 13:40:43 +00:00
Laszlo Ersek e7641171b6 OvmfPkg/OvmfXen: make "PcdPciDisableBusEnumeration" Fixed-at-Build
The OvmfXen platform specifies the dynamic access method for
"PcdPciDisableBusEnumeration" needlessly.

After the DSC file sets the PCD to TRUE by default, the InitializeXen()
function in XenPlatformPei superfluously sets the PCD to TRUE again. There
are no other writes to the PCD in the platform.

Make the PCD Fixed-At-Build, and remove the access (in fact, the whole
InitializeXen() function) from XenPlatformPei.

Cc: Anthony Perard <anthony.perard@citrix.com>
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Julien Grall <julien@xen.org>
Cc: Philippe Mathieu-Daudé <philmd@redhat.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=2122
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20210526201446.12554-20-lersek@redhat.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
2021-06-04 16:01:50 +00:00
Anthony PERARD 71cdb91f31 OvmfPkg/OvmfXen: Set PcdFSBClock
Update gEfiMdePkgTokenSpaceGuid.PcdFSBClock so it can have the correct
value when SecPeiDxeTimerLibCpu start to use it for the APIC timer.

Currently, nothing appear to use the value in PcdFSBClock before
XenPlatformPei had a chance to set it even though TimerLib is included
in modules run before XenPlatformPei.

XenPlatformPei doesn't use any of the functions that would use that
value. No other modules in the PEI phase seems to use the TimerLib
before PcdFSBClock is set. There are currently two other modules in
the PEI phase that needs the TimerLib:
- S3Resume2Pei, but only because LocalApicLib needs it, but nothing is
  using the value from PcdFSBClock.
- CpuMpPei, but I believe it only runs after XenPlatformPei

Before the PEI phase, there's the SEC phase, and SecMain needs
TimerLib because of LocalApicLib. And it initialise the APIC timers
for the debug agent. But I don't think any of the DebugLib that
OvmfXen could use are actually using the *Delay functions in TimerLib,
and so would not use the value from PcdFSBClock which would be
uninitialised.

A simple runtime test showed that TimerLib doesn't use PcdFSBClock
value before it is set.

Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=2490
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20210412133003.146438-8-anthony.perard@citrix.com>
[lersek@redhat.com: cast Freq to UINT32 for PcdSet32S(), not for ASSERT()]
2021-04-13 11:54:58 +00:00
Anthony PERARD c75c640512 OvmfPkg/XenPlatformPei: Calibrate APIC timer frequency
Calculate the frequency of the APIC timer that Xen provides.

Even though the frequency is currently hard-coded, it isn't part of
the public ABI that Xen provides and thus may change at any time. OVMF
needs to determine the frequency by an other mean.

Fortunately, Xen provides a way to determines the frequency of the
TSC, so we can use TSC to calibrate the frequency of the APIC timer.
That information is found in the shared_info page which we map and
unmap once done (XenBusDxe is going to map the page somewhere else).

The shared_info page is mapped at the highest physical address allowed
as it doesn't need to be in the RAM, thus there's a call to update the
page table.

The calculated frequency is only logged in this patch, it will be used
in a following patch.

Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=2490
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20210412133003.146438-7-anthony.perard@citrix.com>
2021-04-13 11:54:58 +00:00
Anthony PERARD 51e0bd28bb OvmfPkg/XenPlatformPei: Map extra physical address
Some information available in a Xen guest can be mapped anywhere in
the physical address space and they don't need to be backed by RAM.
For example, the shared info page.

While it's easier to put those pages anywhere, it is better to avoid
mapping it where the RAM is. It might split a nice 1G guest page table
into 4k pages and thus reducing performance of the guest when it
accesses its memory. Also mapping a page like the shared info page and
then unmapping it or mapping it somewhere else would leave a hole in
the RAM that the guest would propably not be able to use anymore.

So the patch introduces a new function which can be used to 1:1
mapping of guest physical memory above 4G during the PEI phase so we
can map the Xen shared pages outside of memory that can be used by
guest, and as high as possible.

Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20210412133003.146438-6-anthony.perard@citrix.com>
2021-04-13 11:54:58 +00:00
Igor Druzhinin e68c2a22ca OvmfPkg/XenPlatformPei: Use CPUID to get physical address width on Xen
We faced a problem with passing through a PCI device with 64GB BAR to UEFI
guest. The BAR is expectedly programmed into 64-bit PCI aperture at 64G
address which pushes physical address space to 37 bits. That is above
36-bit width that OVMF exposes currently to a guest without tweaking
PcdPciMmio64Size knob.

The reverse calculation using this knob was inhereted from QEMU-KVM
platform code where it serves the purpose of finding max accessible
physical address without necessary trusting emulated CPUID physbits value
(that could be different from host physbits). On Xen we expect to use
CPUID policy to level the data correctly to prevent situations with guest
physbits > host physbits e.g. across migrations.

The next aspect raising concern - resource consumption for DXE IPL page
tables and time required to map the whole address space in case of using
CPUID bits directly. That could be mitigated by enabling support for 1G
pages in DXE IPL configuration. 1G pages are available on most CPUs
produced in the last 10 years and those without don't have many phys bits.

Remove all the redundant code now (including PcdPciMmio64.. handling
that's not used on Xen anyway) and grab physbits directly from CPUID that
should be what baremetal UEFI systems do.

Signed-off-by: Igor Druzhinin <igor.druzhinin@citrix.com>
Message-Id: <1610509335-23314-1-git-send-email-igor.druzhinin@citrix.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Julien Grall <julien@xen.org>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
[lersek@redhat.com: fix up authorship from groups.io-mangled From line]
[lersek@redhat.com: wrap commit message at 74 characters]
2021-01-19 17:00:08 +00:00
Tom Lendacky 45388d046c OvmfPkg: Obtain SEV encryption mask with the new MemEncryptSevLib API
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=3108

The early assembler code performs validation for some of the SEV-related
information, specifically the encryption bit position. The new
MemEncryptSevGetEncryptionMask() interface provides access to this
validated value.

To ensure that we always use a validated encryption mask for an SEV-ES
guest, update all locations that use CPUID to calculate the encryption
mask to use the new interface.

Also, clean up some call areas where extra masking was being performed
and where a function call was being used instead of the local variable
that was just set using the function.

Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
Cc: Rebecca Cran <rebecca@bsdio.com>
Cc: Peter Grehan <grehan@freebsd.org>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Anthony Perard <anthony.perard@citrix.com>
Cc: Julien Grall <julien@xen.org>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <9de678c0d66443c6cc33e004a4cac0a0223c2ebc.1610045305.git.thomas.lendacky@amd.com>
2021-01-07 19:34:39 +00:00
Anthony PERARD 198a8dc9cd OvmfPkg/XenPlatformPei: Ignore missing PCI Host Bridge on Xen PVH
When the device ID of the host bridge is unknown, check if we are
running as a PVH guest as there is no PCI bus in that case.

Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=1689
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20190813113119.14804-26-anthony.perard@citrix.com>
2019-08-21 18:03:49 +02:00
Anthony PERARD 77d35f5008 OvmfPkg/XenPlatformPei: Reserve VGA memory region, to boot Linux
Linux panic if the VGA region isn't reserved.

When Linux is booted on EFI system, it expects the memory at 0xa0000 to
_not_ be conventional memory. Otherwise a variable isn't initialised
properly and Linux panic when a virtual console/terminal is asked to be
created.

See for more detail:
https://lists.xenproject.org/archives/html/xen-devel/2019-03/msg02139.html

Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=1689
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20190813113119.14804-25-anthony.perard@citrix.com>
2019-08-21 18:03:49 +02:00
Anthony PERARD 24465c380a OvmfPkg/XenPlatformPei: Rework memory detection
When running as a Xen PVH guest, there is no CMOS to read the memory
size from.  Rework GetSystemMemorySize(Below|Above)4gb() so they can
work without CMOS by reading the e820 table.

Rework XenPublishRamRegions to also care for the reserved and ACPI
entry in the e820 table. The region that was added by InitializeXen()
isn't needed as that same entry is in the e820 table provided by
hvmloader.

MTRR settings aren't modified anymore, on HVM it's already done by
hvmloader, on PVH it is supposed to have sane default. MTRR will need
to be done properly but keeping what's already been done by programs
that have run before OVMF will do for now.

Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=1689
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20190813113119.14804-24-anthony.perard@citrix.com>
2019-08-21 18:03:49 +02:00
Anthony PERARD a749e1f93b OvmfPkg/XenPlatformPei: no hvmloader: get the E820 table via hypercall
When the Xen PVH entry point has been used, hvmloader hasn't run and
hasn't prepared an E820 table. The only way left to get an E820 table
is to ask Xen via an hypercall.  We keep the result cached to avoid
making a second hypercall which would give the same result.

Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=1689
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20190813113119.14804-23-anthony.perard@citrix.com>
2019-08-21 18:03:49 +02:00
Anthony PERARD 64eac29576 OvmfPkg/XenPlatformPei: Introduce XenPvhDetected
XenPvhDetected() can be used to figure out if OVMF has started via the
Xen PVH entry point.

Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=1689
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20190813113119.14804-21-anthony.perard@citrix.com>
2019-08-21 18:03:49 +02:00
Anthony PERARD 12998837d5 OvmfPkg/XenPlatformPei: Setup HyperPages earlier
We are going to need to make an hypercall in order to retreive the E820
table from the hypervisor before been able to setup the memory.

Calling XenConnect earlier will allow to setup the XenHypercallLib
earlier to allow to make hypercalls.

While here, add some comments in XenConnect().

Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=1689
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20190813113119.14804-20-anthony.perard@citrix.com>
2019-08-21 18:03:49 +02:00
Anthony PERARD 4022f7fa91 OvmfPkg/XenPlatformPei: Introduce XenHvmloaderDetected
This new XenHvmloaderDetected() return true if the hvmloader firmware
has runned before OVMF.

Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=1689
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20190813113119.14804-19-anthony.perard@citrix.com>
2019-08-21 18:03:49 +02:00
Anthony PERARD 80b619d5c4 OvmfPkg/XenPlatformPei: Reinit XenHypercallLib
The XenPlatformPei needs to make hypercalls, but the XenHypercallLib was
initialised before the HyperPage was ready. Now that XenPlatformPei has
initialised the HyperPage, reinitialise the XenHypercallLib.

Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=1689
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20190813113119.14804-18-anthony.perard@citrix.com>
2019-08-21 18:03:49 +02:00
Anthony PERARD 60d265451a OvmfPkg/XenPlatformPei: Grab RSDP from PVH guest start of day struct
Check if there's a start of the day struct provided to PVH guest, save
the ACPI RSDP address for later.

This patch import import arch-x86/hvm/start_info.h from xen.git.

Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=1689
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20190813113119.14804-13-anthony.perard@citrix.com>
2019-08-21 18:03:49 +02:00
Anthony PERARD 594b5002a6 OvmfPkg/XenPlatformPei: Use mXenHvmloaderInfo to get E820
Use the already checked pointer mXenHvmloaderInfo to retrieve the E820
table produced by hvmloader.

Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=1689
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20190813113119.14804-12-anthony.perard@citrix.com>
2019-08-21 18:03:49 +02:00
Anthony PERARD 8651e1ce71 OvmfPkg/XenPlatformPei: Detect OVMF_INFO from hvmloader
EFI_XEN_OVMF_INFO is only useful to retrieve the E820 table. The
mXenHvmloaderInfo isn't used yet, but will be use in a further patch to
retrieve the E820 table.

Also remove the unused pointer from the XenInfo HOB as that information
is only useful in the XenPlatformPei.

Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=1689
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20190813113119.14804-11-anthony.perard@citrix.com>
2019-08-21 18:03:49 +02:00
Anthony PERARD 3b96221f77 OvmfPkg: Introduce XenPlatformPei
Introduce XenPlatformPei, a copy of OvmfPkg/PlatformPei without some
of QEMU specific initialization, Xen does not support QemuFwCfg.

This new module will be adjusted to accommodate Xen PVH.

fw_cfg dependents that have been removed, which are dynamically skipped
when running PlatformPei on Xen:
- GetFirstNonAddress(): controlling the 64-bit PCI MMIO aperture via the
(experimental) "opt/ovmf/X-PciMmio64Mb" file
- GetFirstNonAddress(): honoring the hotplug DIMM area
("etc/reserved-memory-end") in the placement of the 64-bit PCI MMIO
aperture
- NoexecDxeInitialization() is removed, so PcdPropertiesTableEnable and
PcdSetNxForStack are left constant FALSE (not set dynamically from
fw_cfg "opt/ovmf/PcdXxxx")
- MaxCpuCountInitialization(), PublishPeiMemory(): the max CPU count is
not taken from the QemuFwCfgItemSmpCpuCount fw_cfg key;
PcdCpuMaxLogicalProcessorNumber is used intact and
PcdCpuApInitTimeOutInMicroSeconds is never changed or used.
- InitializeXenPlatform(), S3Verification(): S3 is assumed disabled (not
consulting "etc/system-states" via QemuFwCfgS3Enabled()).
- InstallFeatureControlCallback(): the feature control MSR is not set
from "etc/msr_feature_control"
(also removed FeatureControl.c as there is nothing been executed)

Also removed:
- SMRAM/TSEG-related low mem size adjusting (PcdSmmSmramRequire is
assumed FALSE) in PublishPeiMemory(),
- QemuInitializeRam() entirely,

Xen related changes:
- Have removed the module variable mXen, as it should be always true.
- Have the platform PEI initialization fails if Xen has not been
  detected.

Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=1689
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20190813113119.14804-5-anthony.perard@citrix.com>
2019-08-21 18:03:49 +02:00