The reason for reset_stack() introduction is that stack should be
reset twice:
1. Before jumping to C world at the start of _start() function.
2. After jumping from 1:1 mapping world.
Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Sometimes variables are located in .sbss section but it won't
be mapped after MMU will be enabled.
To avoid MMU failures .sbss should be mapped
Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
After introduction of initial pagetables there is no any sense
in dummy_bss variable as bss section will not be empty anymore.
Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Acked-by: Bobby Eshleman <bobbyeshleman@gmail.com>
The patch does two thing:
1. Setup initial pagetables.
2. Enable MMU which end up with code in
cont_after_mmu_is_enabled()
Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Acked-by: Bobby Eshleman <bobbyeshleman@gmail.com>
bss clear cycle requires proper alignment of __bss_start.
ALIGN(PAGE_SIZE) before "*(.bss.page_aligned)" in xen.lds.S
was removed as any contribution to "*(.bss.page_aligned)" have to
specify proper aligntment themselves.
Fixes: cfa0409f7c ("xen/riscv: initialize .bss section")
Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Bobby Eshleman <bobbyeshleman@gmail.com>
The idea was taken from xvisor but the following changes
were done:
* Use only a minimal part of the code enough to enable MMU
* rename {_}setup_initial_pagetables functions
* add an argument for setup_initial_mapping to have
an opportunity to make set PTE flags.
* update setup_initial_pagetables function to map sections
with correct PTE flags.
* Rewrite enable_mmu() to C.
* map linker addresses range to load addresses range without
1:1 mapping. It will be 1:1 only in case when
load_start_addr is equal to linker_start_addr.
* add safety checks such as:
* Xen size is less than page size
* linker addresses range doesn't overlap load addresses
range
* Rework macros {THIRD,SECOND,FIRST,ZEROETH}_{SHIFT,MASK}
* change PTE_LEAF_DEFAULT to RW instead of RWX.
* Remove phys_offset as it is not used now
* Remove alignment of {map, pa}_start &= XEN_PT_LEVEL_MAP_MASK(0);
in setup_inital_mapping() as they should be already aligned.
Make a check that {map_pa}_start are aligned.
* Remove clear_pagetables() as initial pagetables will be
zeroed during bss initialization
* Remove __attribute__((section(".entry")) for setup_initial_pagetables()
as there is no such section in xen.lds.S
* Update the argument of pte_is_valid() to "const pte_t *p"
* Add check that Xen's load address is aligned at 4k boundary
* Refactor setup_initial_pagetables() so it is mapping linker
address range to load address range. After setup needed
permissions for specific section ( such as .text, .rodata, etc )
otherwise RW permission will be set by default.
* Add function to check that requested SATP_MODE is supported
Origin: git@github.com:xvisor/xvisor.git 9be2fdd7
Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Bobby Eshleman <bobbyeshleman@gmail.com>
The GOT sections usage should be avoided in the hypervisor
so to catch such use cases earlier when GOT things are
produced the patch introduces .got and .got.plt sections
and adds asserts that they're empty.
The sections won't be created until they remain
empty otherwise the asserts would cause early failure.
Suggested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
The patch is needed to keep all address of cpu0_boot_stack
PC-relative.
Pseudoinstruction 'la' can be transformed to 'auipc/addi' or
'auipc/l{w|d}'. It depends on the .option directive: nopic and pic
or compiler flags.
Right now, 'la' transforms to 'auipc/l{w|d}', which in case of
cpu0_boot_stack[] will lead to the usage of _GLOBAL_OFFSET_TABLE_
where all addresses will be without counting that it might happen
that linker address != load address ( so addresses inside got
sections will be relative to linker time ).
It happens becuase the compiler from riscv64 docker compiled with
--enable-default-pie:
[user@49295ae49cbe build]$ riscv64-linux-gnu-gcc -v
Using built-in specs.
COLLECT_GCC=riscv64-linux-gnu-gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/riscv64-linux-gnu/12.2.0/lto-wrapper
Target: riscv64-linux-gnu
Configured with: /build/riscv64-linux-gnu-gcc/src/gcc-12.2.0/configure
--prefix=/usr --program-prefix=riscv64-linux-gnu- --with-local-
prefix=/usr/riscv64-linux-gnu --with-sysroot=/usr/riscv64-linux-gnu --
with-build-sysroot=/usr/riscv64-linux-gnu --libdir=/usr/lib --
libexecdir=/usr/lib --target=riscv64-linux-gnu --host=x86_64-pc-linux-
gnu --build=x86_64-pc-linux-gnu --with-system-zlib --with-isl --with-
linker-hash-style=gnu --disable-nls --disable-libunwind-exceptions --
disable-libstdcxx-pch --disable-libssp --disable-multilib --disable-
werror --enable-languages=c,c++ --enable-shared --enable-threads=posix
--enable-__cxa_atexit --enable-clocale=gnu --enable-gnu-unique-object -
-enable-linker-build-id --enable-lto --enable-plugin --enable-install-
libiberty --enable-gnu-indirect-function --enable-default-pie --enable-
checking=release
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 12.2.0 (GCC)
Looking at gcc spec file for the RISC-V architecture:
[user@49295ae49cbe build]$ riscv64-linux-gnu-gcc -dumpspecs | grep -i
pic
--traditional-format %(subtarget_asm_debugging_spec) %{fno-pie|fno-
PIE|fno-pic|fno-PIC:;:-fpic} %{march=*} %{mabi=*} %{mno-relax} %{mbig-
endian} %{mlittle-endian} %(subtarget_asm_spec)%{misa-spec=*}
which means that -fpic is enabled if none of the following options are
present on the command line:
-fno-pie
-fno-PIE
-fno-pic
-fno-PIC
That's the reasons why 'la' is transformed to 'aupic/l{w|d} GOT' and
not be dependent on the toolchain used.
Suggested-by: Jan Beulich <jbeulich@suse.com>
Suggested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
The following changes were made:
* Make GENERIC_BUG_FRAME mandatory for X86
* Update asm/bug.h using generic implementation in <xen/bug.h>
* Update do_invalid_op using generic do_bug_frame()
* Define BUG_DEBUGGER_TRAP_FATAL to debugger_trap_fatal(X86_EXC_GP,regs)
* type of eip variable was changed to 'const void *'
Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
The idea of the patch is to change all <asm/bug.h> to <xen/bug.h> and
keep Xen compilable with adding only minimal amount of changes:
1. It was added "#include <xen/types.h>" to ARM's "<asm/bug.h>" as it
uses uint_{16,32}t in 'struct bug_frame'.
2. It was added '#define BUG_FRAME_STRUCT' which means that ARM hasn't
been switched to generic implementation yet.
3. It was added '#define BUG_FRAME_STRUCT' which means that x86 hasn't
been switched to generic implementation yet.
4. BUGFRAME_* and _start_bug_frame[], _stop_bug_frame_*[] were removed
for ARM & x86 to deal with compilation errors such as:
redundant redeclaration of ...
5. Remove BUG_DISP_WIDTH, BUG_LINE_LO_WIDTH, BUG_LINE_HI_WIDTH from
x86's <asm.bug.h> to not to produce #undef for them and #define again
with the same values as in <xen/bug.h>. These #undef and #define will
be anyway removed in the patch [2]
6. Remove <asm/bug.h> from <x86/acpi/cpufreq/cpufreq.c> and
<drivers/cpufreq/cpufreq.c> as nothing from <xen/bug.h> are used in
<*/cpufreq.c>
In the following two patches x86 and ARM archictectures will be
switched fully:
[1] xen/arm: switch ARM to use generic implementation of bug.h
[2] xen/x86: switch x86 to use generic implemetation of bug.h
Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Julien Grall <jgrall@amazon.com>
The following defines BUG_DISP_WIDTH, BUG_LINE_LO_WIDTH,
BUG_LINE_HI_WIDTH aren't used in ARM so could be purged
as unused.
Requested-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Julien Grall <jgrall@amazon.com>
A large part of the content of the bug.h is repeated among all
architectures, so it was decided to create a new config
CONFIG_GENERIC_BUG_FRAME.
The version of <bug.h> from x86 was taken as the base version.
The patch introduces the following stuff:
* common bug.h header
* generic implementation of do_bug_frame
* new config CONFIG_GENERIC_BUG_FRAME
Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Tested-by: Julien Grall <jgrall@amazon.com>
Acked-by: Julien Grall <jgrall@amazon.com>
The entries in *(.proc.info) are expected to be 4-byte aligned and the
compiler will access them using 4-byte load instructions. On Arm32, the
alignment is strictly enforced by the processor and will result to a data
abort if it is not correct.
However, the linker script doesn't encode this requirement. So we are at
the mercy of the compiler/linker to have padded the previous sections
suitably.
This was spotted when trying to use the upcoming generic bug
infrastructure with the compiler provided by Yocto.
Link: https://lore.kernel.org/xen-devel/6735859208c6dcb7320f89664ae298005f70827b.camel@gmail.com/
Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
The patch introduces an implementation of basic exception handlers:
- to save/restore context
- to handle an exception itself. The handler calls wait_for_interrupt
now, nothing more.
Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
The patch introduces a set of registers which should be saved to and
restored from a stack after an exception occurs and a set of defines
which will be used during exception context saving/restoring.
Originally <asm/processor.h> header was introduced in the patch series
from Bobby so partially it was
re-used and the following changes were done:
- Move all RISCV_CPU_USER_REGS_* to asm/asm-offsets.c
- Remove RISCV_CPU_USER_REGS_OFFSET & RISCV_CPU_USER_REGS_SIZE as
there is no sense in them after RISCV_CPU_USER_REGS_* were moved to
asm/asm-offsets.c
- Remove RISCV_PCPUINFO_* as they aren't needed for current status of
the RISC-V port
- register_t renamed to unsigned long
- rename wait_for_interrupt to wfi
Signed-off-by: Bobby Eshleman <bobby.eshleman@gmail.com>
Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Add check if there is a message 'Hello from C env' presents
in log file to be sure that stack is set and C part of early printk
is working.
Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Because printk() relies on a serial driver (like the ns16550 driver)
and drivers require working virtual memory (ioremap()) there is not
print functionality early in Xen boot.
The patch introduces the basic stuff of early_printk functionality
which will be enough to print 'hello from C environment".
Originally early_printk.{c,h} was introduced by Bobby Eshleman
(https://github.com/glg-rv/xen/commit/a3c9916bbdff7ad6030055bbee7e53d1aab71384)
but some functionality was changed:
early_printk() function was changed in comparison with the original as
common isn't being built now so there is no vscnprintf.
This commit adds early printk implementation built on the putc SBI call.
As sbi_console_putchar() is already being planned for deprecation
it is used temporarily now and will be removed or reworked after
real uart will be ready.
Signed-off-by: Bobby Eshleman <bobby.eshleman@gmail.com>
Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Reviewed-by: Bobby Eshleman <bobby.eshleman@gmail.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
The following changes were done in Xen code base in comparison with OpenSBI:
* Remove "#include <sbi/sbi_const.h>" as most of the stuff inside
it is present in Xen code base.
* Add macros _UL and _ULL as they were in <sbi/sbi_const.h> before
* Add SATP32_MODE_SHIFT/SATP64_MODE_SHIFT/SATP_MODE_SHIFT as they will
be used in riscv/mm.c
* Add CAUSE_IRQ_FLAG which is going to be used insised exception
handler
* Change ulong to unsigned long in macros REG_PTR(...)
* Change s32 to int32_t
Originally authored by Anup Patel <anup.patel@wdc.com>
Origin: https://github.com/riscv-software-src/opensbi.git c45992cc2b12
Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Work with some registers requires csr command which is part of
Zicsr.
Also ISA was changed from r64ima to r64g where G is represented the
“IMAFDZicsr Zifencei” base and extensions so basically it is the same
as it was before plus additional extensions we will need in the
nearest future.
Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
As common isn't built for RISC-V architecture now, accordingly,
common/coverage (where __gconv_* function are defined) isn't built either
but randconfig may decide to enable CONFIG_COVERAGE which will lead to
the following compilation error:
riscv64-linux-gnu-ld: prelink.o: in function `.L0 ':
arch/riscv/early_printk.c:(.text+0x18):
undefined reference to `__gcov_init'
riscv64-linux-gnu-ld: arch/riscv/early_printk.c:(.text+0x40):
undefined reference to `__gcov_exit'
Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
<asm/types.h> should be included because second argument of
early_puts has type 'size_t' which is defined in <asm/types.h>
Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Acked-by: Julien Grall <jgrall@amazon.com>
The patch provides a minimal amount of changes to start
build and run minimal Xen binary at GitLab CI&CD that will
allow continuous checking of the build status of RISC-V Xen.
Except introduction of new files the following changes were done:
* Redefinition of ALIGN define from '.align 2' to '.align 4', as 2 was
incorrect choice done previously.
* ALL_OBJ-y and ALL_LIBS-y were temporary overwritted to produce
a minimal hypervisor image otherwise it will be required to push
huge amount of headers and stubs for common, drivers, libs etc which
aren't necessary for now.
* Section changed from .text to .text.header for start function
to make it the first one executed.
* Rework riscv64/Makefile logic to rebase over changes since the first
RISC-V commit.
RISC-V Xen can be built by the following instructions:
$ CONTAINER=riscv64 ./automation/scripts/containerize \
make XEN_TARGET_ARCH=riscv64 -C xen tiny64_defconfig
$ CONTAINER=riscv64 ./automation/scripts/containerize \
make XEN_TARGET_ARCH=riscv64 -C xen build
Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Oleksii Kurochko