| Message ID | 20240621224946.4083742-1-jmattson@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: x86: Complain about an attempt to change the APIC base address | expand |
Hi Jim,
kernel test robot noticed the following build warnings:
[auto build test WARNING on kvm/queue]
[also build test WARNING on linus/master v6.10-rc5 next-20240625]
[cannot apply to kvm/linux-next]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Jim-Mattson/KVM-x86-Complain-about-an-attempt-to-change-the-APIC-base-address/20240625-181629
base: https://git.kernel.org/pub/scm/virt/kvm/kvm.git queue
patch link: https://lore.kernel.org/r/20240621224946.4083742-1-jmattson%40google.com
patch subject: [PATCH] KVM: x86: Complain about an attempt to change the APIC base address
config: i386-randconfig-141-20240626 (https://download.01.org/0day-ci/archive/20240626/202406260523.KaaWyitN-lkp@intel.com/config)
compiler: gcc-13 (Ubuntu 13.2.0-4ubuntu3) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240626/202406260523.KaaWyitN-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/202406260523.KaaWyitN-lkp@intel.com/
All warnings (new ones prefixed by >>):
In file included from include/asm-generic/bug.h:22,
from arch/x86/include/asm/bug.h:87,
from include/linux/bug.h:5,
from include/linux/alloc_tag.h:8,
from include/linux/percpu.h:5,
from include/linux/context_tracking_state.h:5,
from include/linux/hardirq.h:5,
from include/linux/kvm_host.h:7,
from arch/x86/kvm/lapic.c:20:
arch/x86/kvm/lapic.c: In function 'kvm_lapic_set_base':
include/linux/kern_levels.h:5:25: warning: format '%llx' expects argument of type 'long long unsigned int', but argument 5 has type 'long unsigned int' [-Wformat=]
5 | #define KERN_SOH "\001" /* ASCII Start Of Header */
| ^~~~~~
include/linux/printk.h:436:25: note: in definition of macro 'printk_index_wrap'
436 | _p_func(_fmt, ##__VA_ARGS__); \
| ^~~~
include/linux/printk.h:658:17: note: in expansion of macro 'printk'
658 | printk(fmt, ##__VA_ARGS__); \
| ^~~~~~
include/linux/printk.h:672:9: note: in expansion of macro 'printk_ratelimited'
672 | printk_ratelimited(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
| ^~~~~~~~~~~~~~~~~~
include/linux/kern_levels.h:11:25: note: in expansion of macro 'KERN_SOH'
11 | #define KERN_ERR KERN_SOH "3" /* error conditions */
| ^~~~~~~~
include/linux/printk.h:672:28: note: in expansion of macro 'KERN_ERR'
672 | printk_ratelimited(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
| ^~~~~~~~
include/linux/kvm_host.h:855:9: note: in expansion of macro 'pr_err_ratelimited'
855 | pr_err_ratelimited("kvm [%i]: " fmt, \
| ^~~~~~~~~~~~~~~~~~
include/linux/kvm_host.h:860:9: note: in expansion of macro 'kvm_pr_unimpl'
860 | kvm_pr_unimpl("vcpu%i, guest rIP: 0x%lx " fmt, \
| ^~~~~~~~~~~~~
arch/x86/kvm/lapic.c:2586:17: note: in expansion of macro 'vcpu_unimpl'
2586 | vcpu_unimpl(vcpu, "APIC base %#llx is not %#llx",
| ^~~~~~~~~~~
>> include/linux/kern_levels.h:5:25: warning: format '%llx' expects argument of type 'long long unsigned int', but argument 6 has type 'unsigned int' [-Wformat=]
5 | #define KERN_SOH "\001" /* ASCII Start Of Header */
| ^~~~~~
include/linux/printk.h:436:25: note: in definition of macro 'printk_index_wrap'
436 | _p_func(_fmt, ##__VA_ARGS__); \
| ^~~~
include/linux/printk.h:658:17: note: in expansion of macro 'printk'
658 | printk(fmt, ##__VA_ARGS__); \
| ^~~~~~
include/linux/printk.h:672:9: note: in expansion of macro 'printk_ratelimited'
672 | printk_ratelimited(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
| ^~~~~~~~~~~~~~~~~~
include/linux/kern_levels.h:11:25: note: in expansion of macro 'KERN_SOH'
11 | #define KERN_ERR KERN_SOH "3" /* error conditions */
| ^~~~~~~~
include/linux/printk.h:672:28: note: in expansion of macro 'KERN_ERR'
672 | printk_ratelimited(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
| ^~~~~~~~
include/linux/kvm_host.h:855:9: note: in expansion of macro 'pr_err_ratelimited'
855 | pr_err_ratelimited("kvm [%i]: " fmt, \
| ^~~~~~~~~~~~~~~~~~
include/linux/kvm_host.h:860:9: note: in expansion of macro 'kvm_pr_unimpl'
860 | kvm_pr_unimpl("vcpu%i, guest rIP: 0x%lx " fmt, \
| ^~~~~~~~~~~~~
arch/x86/kvm/lapic.c:2586:17: note: in expansion of macro 'vcpu_unimpl'
2586 | vcpu_unimpl(vcpu, "APIC base %#llx is not %#llx",
| ^~~~~~~~~~~
vim +5 include/linux/kern_levels.h
314ba3520e513a Joe Perches 2012-07-30 4
04d2c8c83d0e3a Joe Perches 2012-07-30 @5 #define KERN_SOH "\001" /* ASCII Start Of Header */
04d2c8c83d0e3a Joe Perches 2012-07-30 6 #define KERN_SOH_ASCII '\001'
04d2c8c83d0e3a Joe Perches 2012-07-30 7
Hi Jim, kernel test robot noticed the following build warnings: [auto build test WARNING on kvm/queue] [also build test WARNING on linus/master v6.10-rc5 next-20240625] [cannot apply to kvm/linux-next] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch#_base_tree_information] url: https://github.com/intel-lab-lkp/linux/commits/Jim-Mattson/KVM-x86-Complain-about-an-attempt-to-change-the-APIC-base-address/20240625-181629 base: https://git.kernel.org/pub/scm/virt/kvm/kvm.git queue patch link: https://lore.kernel.org/r/20240621224946.4083742-1-jmattson%40google.com patch subject: [PATCH] KVM: x86: Complain about an attempt to change the APIC base address config: x86_64-rhel-8.3-rust (https://download.01.org/0day-ci/archive/20240626/202406260749.ZqcsICau-lkp@intel.com/config) compiler: clang version 18.1.5 (https://github.com/llvm/llvm-project 617a15a9eac96088ae5e9134248d8236e34b91b1) reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240626/202406260749.ZqcsICau-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/202406260749.ZqcsICau-lkp@intel.com/ All warnings (new ones prefixed by >>): >> arch/x86/kvm/lapic.c:2587:8: warning: format specifies type 'unsigned long long' but the argument has type 'unsigned long' [-Wformat] 2586 | vcpu_unimpl(vcpu, "APIC base %#llx is not %#llx", | ~~~~~ | %#lx 2587 | apic->base_address, APIC_DEFAULT_PHYS_BASE); | ^~~~~~~~~~~~~~~~~~ include/linux/kvm_host.h:861:44: note: expanded from macro 'vcpu_unimpl' 860 | kvm_pr_unimpl("vcpu%i, guest rIP: 0x%lx " fmt, \ | ~~~ 861 | (vcpu)->vcpu_id, kvm_rip_read(vcpu), ## __VA_ARGS__) | ^~~~~~~~~~~ include/linux/kvm_host.h:856:33: note: expanded from macro 'kvm_pr_unimpl' 855 | pr_err_ratelimited("kvm [%i]: " fmt, \ | ~~~ 856 | task_tgid_nr(current), ## __VA_ARGS__) | ^~~~~~~~~~~ include/linux/printk.h:672:45: note: expanded from macro 'pr_err_ratelimited' 672 | printk_ratelimited(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__) | ~~~ ^~~~~~~~~~~ include/linux/printk.h:658:17: note: expanded from macro 'printk_ratelimited' 658 | printk(fmt, ##__VA_ARGS__); \ | ~~~ ^~~~~~~~~~~ include/linux/printk.h:464:60: note: expanded from macro 'printk' 464 | #define printk(fmt, ...) printk_index_wrap(_printk, fmt, ##__VA_ARGS__) | ~~~ ^~~~~~~~~~~ include/linux/printk.h:436:19: note: expanded from macro 'printk_index_wrap' 436 | _p_func(_fmt, ##__VA_ARGS__); \ | ~~~~ ^~~~~~~~~~~ >> arch/x86/kvm/lapic.c:2587:28: warning: format specifies type 'unsigned long long' but the argument has type 'unsigned int' [-Wformat] 2586 | vcpu_unimpl(vcpu, "APIC base %#llx is not %#llx", | ~~~~~ | %#x 2587 | apic->base_address, APIC_DEFAULT_PHYS_BASE); | ^~~~~~~~~~~~~~~~~~~~~~ include/linux/kvm_host.h:861:44: note: expanded from macro 'vcpu_unimpl' 860 | kvm_pr_unimpl("vcpu%i, guest rIP: 0x%lx " fmt, \ | ~~~ 861 | (vcpu)->vcpu_id, kvm_rip_read(vcpu), ## __VA_ARGS__) | ^~~~~~~~~~~ include/linux/kvm_host.h:856:33: note: expanded from macro 'kvm_pr_unimpl' 855 | pr_err_ratelimited("kvm [%i]: " fmt, \ | ~~~ 856 | task_tgid_nr(current), ## __VA_ARGS__) | ^~~~~~~~~~~ include/linux/printk.h:672:45: note: expanded from macro 'pr_err_ratelimited' 672 | printk_ratelimited(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__) | ~~~ ^~~~~~~~~~~ note: (skipping 1 expansions in backtrace; use -fmacro-backtrace-limit=0 to see all) include/linux/printk.h:464:60: note: expanded from macro 'printk' 464 | #define printk(fmt, ...) printk_index_wrap(_printk, fmt, ##__VA_ARGS__) | ~~~ ^~~~~~~~~~~ include/linux/printk.h:436:19: note: expanded from macro 'printk_index_wrap' 436 | _p_func(_fmt, ##__VA_ARGS__); \ | ~~~~ ^~~~~~~~~~~ arch/x86/include/asm/apicdef.h:15:33: note: expanded from macro 'APIC_DEFAULT_PHYS_BASE' 15 | #define APIC_DEFAULT_PHYS_BASE 0xfee00000 | ^~~~~~~~~~ 2 warnings generated. vim +2587 arch/x86/kvm/lapic.c 2542 2543 void kvm_lapic_set_base(struct kvm_vcpu *vcpu, u64 value) 2544 { 2545 u64 old_value = vcpu->arch.apic_base; 2546 struct kvm_lapic *apic = vcpu->arch.apic; 2547 2548 vcpu->arch.apic_base = value; 2549 2550 if ((old_value ^ value) & MSR_IA32_APICBASE_ENABLE) 2551 kvm_update_cpuid_runtime(vcpu); 2552 2553 if (!apic) 2554 return; 2555 2556 /* update jump label if enable bit changes */ 2557 if ((old_value ^ value) & MSR_IA32_APICBASE_ENABLE) { 2558 if (value & MSR_IA32_APICBASE_ENABLE) { 2559 kvm_apic_set_xapic_id(apic, vcpu->vcpu_id); 2560 static_branch_slow_dec_deferred(&apic_hw_disabled); 2561 /* Check if there are APF page ready requests pending */ 2562 kvm_make_request(KVM_REQ_APF_READY, vcpu); 2563 } else { 2564 static_branch_inc(&apic_hw_disabled.key); 2565 atomic_set_release(&apic->vcpu->kvm->arch.apic_map_dirty, DIRTY); 2566 } 2567 } 2568 2569 if ((old_value ^ value) & X2APIC_ENABLE) { 2570 if (value & X2APIC_ENABLE) 2571 kvm_apic_set_x2apic_id(apic, vcpu->vcpu_id); 2572 else if (value & MSR_IA32_APICBASE_ENABLE) 2573 kvm_apic_set_xapic_id(apic, vcpu->vcpu_id); 2574 } 2575 2576 if ((old_value ^ value) & (MSR_IA32_APICBASE_ENABLE | X2APIC_ENABLE)) { 2577 kvm_make_request(KVM_REQ_APICV_UPDATE, vcpu); 2578 static_call_cond(kvm_x86_set_virtual_apic_mode)(vcpu); 2579 } 2580 2581 apic->base_address = apic->vcpu->arch.apic_base & 2582 MSR_IA32_APICBASE_BASE; 2583 2584 if ((value & MSR_IA32_APICBASE_ENABLE) && 2585 apic->base_address != APIC_DEFAULT_PHYS_BASE) { 2586 vcpu_unimpl(vcpu, "APIC base %#llx is not %#llx", > 2587 apic->base_address, APIC_DEFAULT_PHYS_BASE); 2588 kvm_set_apicv_inhibit(apic->vcpu->kvm, 2589 APICV_INHIBIT_REASON_APIC_BASE_MODIFIED); 2590 } 2591 } 2592
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index acd7d48100a1..5284dddab337 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -2583,6 +2583,8 @@ void kvm_lapic_set_base(struct kvm_vcpu *vcpu, u64 value) if ((value & MSR_IA32_APICBASE_ENABLE) && apic->base_address != APIC_DEFAULT_PHYS_BASE) { + vcpu_unimpl(vcpu, "APIC base %#llx is not %#llx", + apic->base_address, APIC_DEFAULT_PHYS_BASE); kvm_set_apicv_inhibit(apic->vcpu->kvm, APICV_INHIBIT_REASON_APIC_BASE_MODIFIED); }
KVM does not support changing the APIC's base address. Prior to commit 3743c2f02517 ("KVM: x86: inhibit APICv/AVIC on changes to APIC ID or APIC base"), it emitted a rate-limited warning about this. Now, it's just silently broken. Use vcpu_unimpl() to complain about this unsupported operation. Even a rate-limited error message is better than complete silence. Fixes: 3743c2f02517 ("KVM: x86: inhibit APICv/AVIC on changes to APIC ID or APIC base") Signed-off-by: Jim Mattson <jmattson@google.com> --- arch/x86/kvm/lapic.c | 2 ++ 1 file changed, 2 insertions(+)