* Re: [PATCH] x86/fred: Fix early boot failures on SEV-ES/SNP guests
[not found] <20260205051030.1225975-1-nikunj@amd.com>
@ 2026-02-05 10:41 ` kernel test robot
2026-02-06 3:31 ` Nikunj A. Dadhania
2026-02-05 12:35 ` kernel test robot
1 sibling, 1 reply; 4+ messages in thread
From: kernel test robot @ 2026-02-05 10:41 UTC (permalink / raw)
To: Nikunj A Dadhania, linux-kernel, kvm, bp, thomas.lendacky
Cc: llvm, oe-kbuild-all, tglx, mingo, dave.hansen, hpa, xin, seanjc,
pbonzini, x86, jon.grimm, nikunj, stable
Hi Nikunj,
kernel test robot noticed the following build warnings:
[auto build test WARNING on 3c2ca964f75460093a8aad6b314a6cd558e80e66]
url: https://github.com/intel-lab-lkp/linux/commits/Nikunj-A-Dadhania/x86-fred-Fix-early-boot-failures-on-SEV-ES-SNP-guests/20260205-131359
base: 3c2ca964f75460093a8aad6b314a6cd558e80e66
patch link: https://lore.kernel.org/r/20260205051030.1225975-1-nikunj%40amd.com
patch subject: [PATCH] x86/fred: Fix early boot failures on SEV-ES/SNP guests
config: x86_64-kexec (https://download.01.org/0day-ci/archive/20260205/202602051859.vGTf24Nk-lkp@intel.com/config)
compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260205/202602051859.vGTf24Nk-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202602051859.vGTf24Nk-lkp@intel.com/
All warnings (new ones prefixed by >>):
arch/x86/entry/entry_fred.c:213:11: error: call to undeclared function 'user_exc_vmm_communication'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
213 | return user_exc_vmm_communication(regs, error_code);
| ^
>> arch/x86/entry/entry_fred.c:213:4: warning: void function 'fred_hwexc' should not return a value [-Wreturn-mismatch]
213 | return user_exc_vmm_communication(regs, error_code);
| ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
arch/x86/entry/entry_fred.c:215:11: error: call to undeclared function 'kernel_exc_vmm_communication'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
215 | return kernel_exc_vmm_communication(regs, error_code);
| ^
arch/x86/entry/entry_fred.c:215:4: warning: void function 'fred_hwexc' should not return a value [-Wreturn-mismatch]
215 | return kernel_exc_vmm_communication(regs, error_code);
| ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
2 warnings and 2 errors generated.
vim +/fred_hwexc +213 arch/x86/entry/entry_fred.c
180
181 static noinstr void fred_hwexc(struct pt_regs *regs, unsigned long error_code)
182 {
183 /* Optimize for #PF. That's the only exception which matters performance wise */
184 if (likely(regs->fred_ss.vector == X86_TRAP_PF))
185 return exc_page_fault(regs, error_code);
186
187 switch (regs->fred_ss.vector) {
188 case X86_TRAP_DE: return exc_divide_error(regs);
189 case X86_TRAP_DB: return fred_exc_debug(regs);
190 case X86_TRAP_BR: return exc_bounds(regs);
191 case X86_TRAP_UD: return exc_invalid_op(regs);
192 case X86_TRAP_NM: return exc_device_not_available(regs);
193 case X86_TRAP_DF: return exc_double_fault(regs, error_code);
194 case X86_TRAP_TS: return exc_invalid_tss(regs, error_code);
195 case X86_TRAP_NP: return exc_segment_not_present(regs, error_code);
196 case X86_TRAP_SS: return exc_stack_segment(regs, error_code);
197 case X86_TRAP_GP: return exc_general_protection(regs, error_code);
198 case X86_TRAP_MF: return exc_coprocessor_error(regs);
199 case X86_TRAP_AC: return exc_alignment_check(regs, error_code);
200 case X86_TRAP_XF: return exc_simd_coprocessor_error(regs);
201
202 #ifdef CONFIG_X86_MCE
203 case X86_TRAP_MC: return fred_exc_machine_check(regs);
204 #endif
205 #ifdef CONFIG_INTEL_TDX_GUEST
206 case X86_TRAP_VE: return exc_virtualization_exception(regs);
207 #endif
208 #ifdef CONFIG_X86_CET
209 case X86_TRAP_CP: return exc_control_protection(regs, error_code);
210 #endif
211 case X86_TRAP_VC:
212 if (user_mode(regs))
> 213 return user_exc_vmm_communication(regs, error_code);
214 else
215 return kernel_exc_vmm_communication(regs, error_code);
216 default: return fred_bad_type(regs, error_code);
217 }
218
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] x86/fred: Fix early boot failures on SEV-ES/SNP guests
[not found] <20260205051030.1225975-1-nikunj@amd.com>
2026-02-05 10:41 ` [PATCH] x86/fred: Fix early boot failures on SEV-ES/SNP guests kernel test robot
@ 2026-02-05 12:35 ` kernel test robot
1 sibling, 0 replies; 4+ messages in thread
From: kernel test robot @ 2026-02-05 12:35 UTC (permalink / raw)
To: Nikunj A Dadhania, linux-kernel, kvm, bp, thomas.lendacky
Cc: llvm, oe-kbuild-all, tglx, mingo, dave.hansen, hpa, xin, seanjc,
pbonzini, x86, jon.grimm, nikunj, stable
Hi Nikunj,
kernel test robot noticed the following build errors:
[auto build test ERROR on 3c2ca964f75460093a8aad6b314a6cd558e80e66]
url: https://github.com/intel-lab-lkp/linux/commits/Nikunj-A-Dadhania/x86-fred-Fix-early-boot-failures-on-SEV-ES-SNP-guests/20260205-131359
base: 3c2ca964f75460093a8aad6b314a6cd558e80e66
patch link: https://lore.kernel.org/r/20260205051030.1225975-1-nikunj%40amd.com
patch subject: [PATCH] x86/fred: Fix early boot failures on SEV-ES/SNP guests
config: x86_64-kexec (https://download.01.org/0day-ci/archive/20260205/202602052054.J3CEkmKB-lkp@intel.com/config)
compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260205/202602052054.J3CEkmKB-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202602052054.J3CEkmKB-lkp@intel.com/
All errors (new ones prefixed by >>):
>> arch/x86/entry/entry_fred.c:213:11: error: call to undeclared function 'user_exc_vmm_communication'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
213 | return user_exc_vmm_communication(regs, error_code);
| ^
arch/x86/entry/entry_fred.c:213:4: warning: void function 'fred_hwexc' should not return a value [-Wreturn-mismatch]
213 | return user_exc_vmm_communication(regs, error_code);
| ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> arch/x86/entry/entry_fred.c:215:11: error: call to undeclared function 'kernel_exc_vmm_communication'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
215 | return kernel_exc_vmm_communication(regs, error_code);
| ^
arch/x86/entry/entry_fred.c:215:4: warning: void function 'fred_hwexc' should not return a value [-Wreturn-mismatch]
215 | return kernel_exc_vmm_communication(regs, error_code);
| ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
2 warnings and 2 errors generated.
vim +/user_exc_vmm_communication +213 arch/x86/entry/entry_fred.c
180
181 static noinstr void fred_hwexc(struct pt_regs *regs, unsigned long error_code)
182 {
183 /* Optimize for #PF. That's the only exception which matters performance wise */
184 if (likely(regs->fred_ss.vector == X86_TRAP_PF))
185 return exc_page_fault(regs, error_code);
186
187 switch (regs->fred_ss.vector) {
188 case X86_TRAP_DE: return exc_divide_error(regs);
189 case X86_TRAP_DB: return fred_exc_debug(regs);
190 case X86_TRAP_BR: return exc_bounds(regs);
191 case X86_TRAP_UD: return exc_invalid_op(regs);
192 case X86_TRAP_NM: return exc_device_not_available(regs);
193 case X86_TRAP_DF: return exc_double_fault(regs, error_code);
194 case X86_TRAP_TS: return exc_invalid_tss(regs, error_code);
195 case X86_TRAP_NP: return exc_segment_not_present(regs, error_code);
196 case X86_TRAP_SS: return exc_stack_segment(regs, error_code);
197 case X86_TRAP_GP: return exc_general_protection(regs, error_code);
198 case X86_TRAP_MF: return exc_coprocessor_error(regs);
199 case X86_TRAP_AC: return exc_alignment_check(regs, error_code);
200 case X86_TRAP_XF: return exc_simd_coprocessor_error(regs);
201
202 #ifdef CONFIG_X86_MCE
203 case X86_TRAP_MC: return fred_exc_machine_check(regs);
204 #endif
205 #ifdef CONFIG_INTEL_TDX_GUEST
206 case X86_TRAP_VE: return exc_virtualization_exception(regs);
207 #endif
208 #ifdef CONFIG_X86_CET
209 case X86_TRAP_CP: return exc_control_protection(regs, error_code);
210 #endif
211 case X86_TRAP_VC:
212 if (user_mode(regs))
> 213 return user_exc_vmm_communication(regs, error_code);
214 else
> 215 return kernel_exc_vmm_communication(regs, error_code);
216 default: return fred_bad_type(regs, error_code);
217 }
218
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] x86/fred: Fix early boot failures on SEV-ES/SNP guests
2026-02-05 10:41 ` [PATCH] x86/fred: Fix early boot failures on SEV-ES/SNP guests kernel test robot
@ 2026-02-06 3:31 ` Nikunj A. Dadhania
2026-02-06 9:34 ` Xin Li
0 siblings, 1 reply; 4+ messages in thread
From: Nikunj A. Dadhania @ 2026-02-06 3:31 UTC (permalink / raw)
To: kernel test robot, linux-kernel, kvm, bp, thomas.lendacky
Cc: llvm, oe-kbuild-all, tglx, mingo, dave.hansen, hpa, xin, seanjc,
pbonzini, x86, jon.grimm, stable
On 2/5/2026 4:11 PM, kernel test robot wrote:
> Hi Nikunj,
>
> kernel test robot noticed the following build warnings:
>
> [auto build test WARNING on 3c2ca964f75460093a8aad6b314a6cd558e80e66]
>
> url: https://github.com/intel-lab-lkp/linux/commits/Nikunj-A-Dadhania/x86-fred-Fix-early-boot-failures-on-SEV-ES-SNP-guests/20260205-131359
> base: 3c2ca964f75460093a8aad6b314a6cd558e80e66
> patch link: https://lore.kernel.org/r/20260205051030.1225975-1-nikunj%40amd.com
> patch subject: [PATCH] x86/fred: Fix early boot failures on SEV-ES/SNP guests
> config: x86_64-kexec (https://download.01.org/0day-ci/archive/20260205/202602051859.vGTf24Nk-lkp@intel.com/config)
> compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260205/202602051859.vGTf24Nk-lkp@intel.com/reproduce)
>
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@intel.com>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202602051859.vGTf24Nk-lkp@intel.com/
>
> All warnings (new ones prefixed by >>):
>
> arch/x86/entry/entry_fred.c:213:11: error: call to undeclared function 'user_exc_vmm_communication'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
> 213 | return user_exc_vmm_communication(regs, error_code);
> | ^
>>> arch/x86/entry/entry_fred.c:213:4: warning: void function 'fred_hwexc' should not return a value [-Wreturn-mismatch]
> 213 | return user_exc_vmm_communication(regs, error_code);
> | ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> arch/x86/entry/entry_fred.c:215:11: error: call to undeclared function 'kernel_exc_vmm_communication'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
> 215 | return kernel_exc_vmm_communication(regs, error_code);
> | ^
> arch/x86/entry/entry_fred.c:215:4: warning: void function 'fred_hwexc' should not return a value [-Wreturn-mismatch]
> 215 | return kernel_exc_vmm_communication(regs, error_code);
> | ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 2 warnings and 2 errors generated.
>
>
Thanks for the report, below patch should solve the problem:
diff --git a/arch/x86/entry/entry_fred.c b/arch/x86/entry/entry_fred.c
index 7a8659f19441..9946b9e96692 100644
--- a/arch/x86/entry/entry_fred.c
+++ b/arch/x86/entry/entry_fred.c
@@ -208,11 +208,15 @@ static noinstr void fred_hwexc(struct pt_regs *regs, unsigned long error_code)
#ifdef CONFIG_X86_CET
case X86_TRAP_CP: return exc_control_protection(regs, error_code);
#endif
+
+#ifdef CONFIG_AMD_MEM_ENCRYPT
case X86_TRAP_VC:
if (user_mode(regs))
return user_exc_vmm_communication(regs, error_code);
else
return kernel_exc_vmm_communication(regs, error_code);
+#endif
+
default: return fred_bad_type(regs, error_code);
}
Regards
Nikunj
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] x86/fred: Fix early boot failures on SEV-ES/SNP guests
2026-02-06 3:31 ` Nikunj A. Dadhania
@ 2026-02-06 9:34 ` Xin Li
0 siblings, 0 replies; 4+ messages in thread
From: Xin Li @ 2026-02-06 9:34 UTC (permalink / raw)
To: Nikunj A. Dadhania
Cc: kernel test robot, linux-kernel, kvm, bp, thomas.lendacky, llvm,
oe-kbuild-all, tglx, mingo, dave.hansen, hpa, seanjc, pbonzini,
x86, jon.grimm, stable
> On Feb 5, 2026, at 7:31 PM, Nikunj A. Dadhania <nikunj@amd.com> wrote:
>
> if (user_mode(regs))
> return user_exc_vmm_communication(regs, error_code);
> else
> return kernel_exc_vmm_communication(regs, error_code);
Please rewrite this piece of code, like how X86_TRAP_DB is handled today.
Should kernel #VC be handled at a higher level RSP? You can check FRED #DB settings.
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2026-02-06 9:35 UTC | newest]
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[not found] <20260205051030.1225975-1-nikunj@amd.com>
2026-02-05 10:41 ` [PATCH] x86/fred: Fix early boot failures on SEV-ES/SNP guests kernel test robot
2026-02-06 3:31 ` Nikunj A. Dadhania
2026-02-06 9:34 ` Xin Li
2026-02-05 12:35 ` kernel test robot
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