From: Denis Mukhin <dmuk...@ford.com> The new toolchain baseline knows the rdrand/rdseed instructions, no need to carry the workaround in the code.
Resolves: https://gitlab.com/xen-project/xen/-/work_items/208 Signed-off-by: Denis Mukhin <dmuk...@ford.com> --- Changes since v2: - updated arch_get_random() - Link to v2: https://lore.kernel.org/xen-devel/20250403182250.3329498-6-dmuk...@ford.com/ --- xen/arch/x86/arch.mk | 2 -- xen/arch/x86/include/asm/random.h | 2 +- xen/arch/x86/x86_emulate/0fc7.c | 15 +++++---------- 3 files changed, 6 insertions(+), 13 deletions(-) diff --git a/xen/arch/x86/arch.mk b/xen/arch/x86/arch.mk index 3bbaee2a44..5577bf6241 100644 --- a/xen/arch/x86/arch.mk +++ b/xen/arch/x86/arch.mk @@ -10,9 +10,7 @@ CFLAGS += -msoft-float $(call cc-options-add,CFLAGS,CC,$(EMBEDDED_EXTRA_CFLAGS)) $(call cc-option-add,CFLAGS,CC,-Wnested-externs) -$(call as-option-add,CFLAGS,CC,"rdrand %eax",-DHAVE_AS_RDRAND) $(call as-option-add,CFLAGS,CC,"xsaveopt (%rax)",-DHAVE_AS_XSAVEOPT) -$(call as-option-add,CFLAGS,CC,"rdseed %eax",-DHAVE_AS_RDSEED) $(call as-option-add,CFLAGS,CC,"clwb (%rax)",-DHAVE_AS_CLWB) $(call as-option-add,CFLAGS,CC,".equ \"x\"$(comma)1",-DHAVE_AS_QUOTED_SYM) $(call as-option-add,CFLAGS,CC,"movdiri %rax$(comma)(%rax)",-DHAVE_AS_MOVDIR) diff --git a/xen/arch/x86/include/asm/random.h b/xen/arch/x86/include/asm/random.h index 9e1fe0bc1d..e1c1c765e1 100644 --- a/xen/arch/x86/include/asm/random.h +++ b/xen/arch/x86/include/asm/random.h @@ -8,7 +8,7 @@ static inline unsigned int arch_get_random(void) unsigned int val = 0; if ( cpu_has(¤t_cpu_data, X86_FEATURE_RDRAND) ) - asm volatile ( ".byte 0x0f,0xc7,0xf0" : "+a" (val) ); + asm volatile ( "rdrand %0" : "=a" (val) ); return val; } diff --git a/xen/arch/x86/x86_emulate/0fc7.c b/xen/arch/x86/x86_emulate/0fc7.c index 5268d5cafd..58c8f79501 100644 --- a/xen/arch/x86/x86_emulate/0fc7.c +++ b/xen/arch/x86/x86_emulate/0fc7.c @@ -32,7 +32,6 @@ int x86emul_0fc7(struct x86_emulate_state *s, return X86EMUL_UNRECOGNIZED; case 6: /* rdrand */ -#ifdef HAVE_AS_RDRAND generate_exception_if(s->vex.pfx >= vex_f3, X86_EXC_UD); host_and_vcpu_must_have(rdrand); *dst = s->ea; @@ -43,12 +42,12 @@ int x86emul_0fc7(struct x86_emulate_state *s, : "=r" (dst->val), ASM_FLAG_OUT("=@ccc", "=qm") (carry) ); break; default: -# ifdef __x86_64__ +#ifdef __x86_64__ asm ( "rdrand %k0" ASM_FLAG_OUT(, "; setc %1") : "=r" (dst->val), ASM_FLAG_OUT("=@ccc", "=qm") (carry) ); break; case 8: -# endif +#endif asm ( "rdrand %0" ASM_FLAG_OUT(, "; setc %1") : "=r" (dst->val), ASM_FLAG_OUT("=@ccc", "=qm") (carry) ); break; @@ -57,9 +56,6 @@ int x86emul_0fc7(struct x86_emulate_state *s, if ( carry ) regs->eflags |= X86_EFLAGS_CF; break; -#else - return X86EMUL_UNIMPLEMENTED; -#endif case 7: /* rdseed / rdpid */ if ( s->vex.pfx == vex_f3 ) /* rdpid */ @@ -77,7 +73,7 @@ int x86emul_0fc7(struct x86_emulate_state *s, dst->bytes = 4; break; } -#ifdef HAVE_AS_RDSEED + generate_exception_if(s->vex.pfx >= vex_f3, X86_EXC_UD); host_and_vcpu_must_have(rdseed); *dst = s->ea; @@ -88,12 +84,12 @@ int x86emul_0fc7(struct x86_emulate_state *s, : "=r" (dst->val), ASM_FLAG_OUT("=@ccc", "=qm") (carry) ); break; default: -# ifdef __x86_64__ +#ifdef __x86_64__ asm ( "rdseed %k0" ASM_FLAG_OUT(, "; setc %1") : "=r" (dst->val), ASM_FLAG_OUT("=@ccc", "=qm") (carry) ); break; case 8: -# endif +#endif asm ( "rdseed %0" ASM_FLAG_OUT(, "; setc %1") : "=r" (dst->val), ASM_FLAG_OUT("=@ccc", "=qm") (carry) ); break; @@ -102,7 +98,6 @@ int x86emul_0fc7(struct x86_emulate_state *s, if ( carry ) regs->eflags |= X86_EFLAGS_CF; break; -#endif } } else -- 2.34.1
