Currently, running SetVirtualAddressMap() and passing the physical
address of the virtual map array was working only by a lucky coincidence
because the memory was present in the EFI page table too. Until Toshi
went and booted this on a big HP box - the krealloc() manner of resizing
the memmap we're doing did allocate from such physical addresses which
were not mapped anymore and boom:
http://lkml.kernel.org/r/1386806463.1791.295.camel@misato.fc.hp.com
One way to take care of that issue is to reimplement the krealloc thing
but with pages. We start with contiguous pages of order 1, i.e. 2 pages,
and when we deplete that memory (shouldn't happen all that often but you
know firmware) we realloc the next power-of-two pages.
Having the pages, it is much more handy and easy to map them into the
EFI page table with the already existing mapping code which we're using
for building the virtual mappings.
Thanks to Toshi Kani and Matt for the great debugging help.
Reported-by: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Tested-by: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
This is very useful for debugging issues with the recently added
pagetable switching code for EFI virtual mode.
Signed-off-by: Borislav Petkov <bp@suse.de>
Tested-by: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
We do not enable the new efi memmap on 32-bit and thus we need to run
runtime_code_page_mkexec() unconditionally there. Fix that.
Reported-and-tested-by: Lejun Zhu <lejun.zhu@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Add a new setup_data type SETUP_EFI for kexec use. Passing the saved
fw_vendor, runtime, config tables and EFI runtime mappings.
When entering virtual mode, directly mapping the EFI runtime regions
which we passed in previously. And skip the step to call
SetVirtualAddressMap().
Specially for HP z420 workstation we need save the smbios physical
address. The kernel boot sequence proceeds in the following order.
Step 2 requires efi.smbios to be the physical address. However, I found
that on HP z420 EFI system table has a virtual address of SMBIOS in step
1. Hence, we need set it back to the physical address with the smbios
in efi_setup_data. (When it is still the physical address, it simply
sets the same value.)
1. efi_init() - Set efi.smbios from EFI system table
2. dmi_scan_machine() - Temporary map efi.smbios to access SMBIOS table
3. efi_enter_virtual_mode() - Map EFI ranges
Tested on ovmf+qemu, lenovo thinkpad, a dell laptop and an
HP z420 workstation.
Signed-off-by: Dave Young <dyoung@redhat.com>
Tested-by: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Kexec kernel will use saved runtime virtual mapping, so add a new
function efi_map_region_fixed() for directly mapping a md to md->virt.
The md is passed in from 1st kernel, the virtual addr is saved in
md->virt_addr.
Signed-off-by: Dave Young <dyoung@redhat.com>
Acked-by: Borislav Petkov <bp@suse.de>
Tested-by: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
We map the EFI regions needed for runtime services non-contiguously,
with preserved alignment on virtual addresses starting from -4G down
for a total max space of 64G. This way, we provide for stable runtime
services addresses across kernels so that a kexec'd kernel can still use
them.
Thus, they're mapped in a separate pagetable so that we don't pollute
the kernel namespace.
Add an efi= kernel command line parameter for passing miscellaneous
options and chicken bits from the command line.
While at it, add a chicken bit called "efi=old_map" which can be used as
a fallback to the old runtime services mapping method in case there's
some b0rkage with a particular EFI implementation (haha, it is hard to
hold up the sarcasm here...).
Also, add the UEFI RT VA space to Documentation/x86/x86_64/mm.txt.
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
efi_call_phys_prelog() sets up a 1:1 mapping of the physical address
range in swapper_pg_dir. Instead of replacing then restoring entries
in swapper_pg_dir we should be using initial_page_table which already
contains the 1:1 mapping.
It's safe to blindly switch back to swapper_pg_dir in the epilog
because the physical EFI routines are only called before
efi_enter_virtual_mode(), e.g. before any user processes have been
forked. Therefore, we don't need to track which pgd was in %cr3 when
we entered the prelog.
The previous code actually contained a bug because it assumed that the
kernel was loaded at a physical address within the first 8MB of ram,
usually at 0x100000. However, this isn't the case with a
CONFIG_RELOCATABLE=y kernel which could have been loaded anywhere in
the physical address space.
Also delete the ancient (and bogus) comments about the page table
being restored after the lock is released. There is no locking.
Cc: Matthew Garrett <mjg@redhat.com>
Cc: Darrent Hart <dvhart@linux.intel.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Link: http://lkml.kernel.org/r/1323346250.3894.74.camel@mfleming-mobl1.ger.corp.intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
We want to clean up the chain of includes stumbling through
module.h, and when we do that, we'll see:
CC arch/x86/platform/efi/efi_32.o
efi/efi_32.c: In function ‘efi_call_phys_prelog’:
efi/efi_32.c:80: error: implicit declaration of function ‘get_cpu_gdt_table’
efi/efi_32.c:82: error: implicit declaration of function ‘load_gdt’
make[4]: *** [arch/x86/platform/efi/efi_32.o] Error 1
Include asm/desc.h so that there are no implicit include assumptions.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Borislav Petkov