| Message ID | 20241111104902.985611-1-andrew.cooper3@citrix.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | x86/trampoline: Change type of trampoline_phys to uint32_t | expand |
On 11.11.2024 11:49, Andrew Cooper wrote: > As now documented, this variable holds a page aligned value less than 1M. > > However, head.S fills it using 4-byte stores, and reloc_trampoline() is > compiled for both 32bit and 64bit, where unsigned long is a different size. > > This happens to work because of the range of the value, but switch to uint32_t > to make it explicit. > > Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> Acked-by: Jan Beulich <jbeulich@suse.com> noting that ... > --- a/xen/arch/x86/boot/reloc-trampoline.c > +++ b/xen/arch/x86/boot/reloc-trampoline.c > @@ -15,7 +15,7 @@ void reloc_trampoline64(void) > #error Unknown architecture > #endif > { > - unsigned long phys = trampoline_phys; > + uint32_t phys = trampoline_phys; > const int32_t *trampoline_ptr; ... this change shouldn't really be needed (but is okay-ish to have). Jan
diff --git a/xen/arch/x86/boot/reloc-trampoline.c b/xen/arch/x86/boot/reloc-trampoline.c index 0a74c1e75a4c..d5548eb08f85 100644 --- a/xen/arch/x86/boot/reloc-trampoline.c +++ b/xen/arch/x86/boot/reloc-trampoline.c @@ -15,7 +15,7 @@ void reloc_trampoline64(void) #error Unknown architecture #endif { - unsigned long phys = trampoline_phys; + uint32_t phys = trampoline_phys; const int32_t *trampoline_ptr; /* diff --git a/xen/arch/x86/efi/efi-boot.h b/xen/arch/x86/efi/efi-boot.h index 3133985c88f8..7930b7c73892 100644 --- a/xen/arch/x86/efi/efi-boot.h +++ b/xen/arch/x86/efi/efi-boot.h @@ -235,7 +235,7 @@ static void __init noreturn efi_arch_post_exit_boot(void) u64 cr4 = XEN_MINIMAL_CR4 & ~X86_CR4_PGE, efer; efi_arch_relocate_image(__XEN_VIRT_START - xen_phys_start); - memcpy((void *)trampoline_phys, trampoline_start, cfg.size); + memcpy(_p(trampoline_phys), trampoline_start, cfg.size); /* * We're in physical mode right now (i.e. identity map), so a regular diff --git a/xen/arch/x86/include/asm/trampoline.h b/xen/arch/x86/include/asm/trampoline.h index 838c2f0b6fcd..8c1e0b48c2c9 100644 --- a/xen/arch/x86/include/asm/trampoline.h +++ b/xen/arch/x86/include/asm/trampoline.h @@ -52,7 +52,7 @@ extern char trampoline_start[], trampoline_end[]; * the 1M boundary (as the trampoline contains 16-bit code), and must be 4k * aligned (SIPI requirement for APs). */ -extern unsigned long trampoline_phys; +extern uint32_t trampoline_phys; /* * Calculate the physical address of a symbol in the trampoline. diff --git a/xen/arch/x86/smpboot.c b/xen/arch/x86/smpboot.c index 9e79c1a6d6e6..7f0f57bb8ffe 100644 --- a/xen/arch/x86/smpboot.c +++ b/xen/arch/x86/smpboot.c @@ -39,7 +39,7 @@ #include <irq_vectors.h> #include <mach_apic.h> -unsigned long __read_mostly trampoline_phys; +uint32_t __ro_after_init trampoline_phys; enum ap_boot_method __read_mostly ap_boot_method = AP_BOOT_NORMAL; /* representing HT siblings of each logical CPU */
As now documented, this variable holds a page aligned value less than 1M. However, head.S fills it using 4-byte stores, and reloc_trampoline() is compiled for both 32bit and 64bit, where unsigned long is a different size. This happens to work because of the range of the value, but switch to uint32_t to make it explicit. Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> --- CC: Jan Beulich <JBeulich@suse.com> CC: Roger Pau Monné <roger.pau@citrix.com> CC: Frediano Ziglio <frediano.ziglio@cloud.com> Bloat-o-meter reports a marginal code-gen improvement: add/remove: 0/0 grow/shrink: 5/7 up/down: 26/-85 (-59) Function old new delta enter_state_helper.cold 1091 1100 +9 __start_xen 8827 8835 +8 __cpu_up.cold 199 204 +5 intel_unlock_cpuid_leaves 102 104 +2 acpi_enter_sleep_state 397 399 +2 efi_arch_memory_setup 538 537 -1 arch_init_memory 632 631 -1 trampoline_phys 8 4 -4 do_platform_op 5439 5431 -8 compat_platform_op 5450 5442 -8 reloc_trampoline64 137 122 -15 __cpu_up 1513 1465 -48 --- xen/arch/x86/boot/reloc-trampoline.c | 2 +- xen/arch/x86/efi/efi-boot.h | 2 +- xen/arch/x86/include/asm/trampoline.h | 2 +- xen/arch/x86/smpboot.c | 2 +- 4 files changed, 4 insertions(+), 4 deletions(-)