This patch adds three architecture specific interfaces and x86
implementations used by `perf kvm`:
- kvm_arch_vcpu_get_frame_pointer: Return the frame pointer of vcpu,
for x86 it's RBP, and for arm64 it's x29.
- kvm_arch_vcpu_read_virt: Read data from a virtual address
of the given guest vm.
- kvm_arch_vcpu_is_64bit: Return whether the vcpu is working in 64-bit
mode. It's used for determining the size of a stack frame.
Since arm64 hasn't provided some foundational infrastructure,
stub the arm64 implementation for now because it's a bit complex.
Signed-off-by: Tianyi Liu <i.pear@outlook.com>
---
arch/arm64/kvm/arm.c | 17 +++++++++++++++++
arch/x86/kvm/x86.c | 18 ++++++++++++++++++
include/linux/kvm_host.h | 4 ++++
3 files changed, 39 insertions(+)
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 4866b3f7b..b57b88c58 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -571,6 +571,23 @@ unsigned long kvm_arch_vcpu_get_ip(struct kvm_vcpu *vcpu)
{
return *vcpu_pc(vcpu);
}
+
+unsigned long kvm_arch_vcpu_get_frame_pointer(struct kvm_vcpu *vcpu)
+{
+ /* TODO: implement */
+ return NULL;
+}
+
+bool kvm_arch_vcpu_read_virt(struct kvm_vcpu *vcpu, void *addr, void *dest, unsigned int length)
+{
+ /* TODO: implement */
+ return false;
+}
+
+bool kvm_arch_vcpu_is_64bit(struct kvm_vcpu *vcpu)
+{
+ return !vcpu_mode_is_32bit(vcpu);
+}
#endif
static int kvm_vcpu_initialized(struct kvm_vcpu *vcpu)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 9f18b06bb..17dea02b7 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -12904,6 +12904,24 @@ unsigned long kvm_arch_vcpu_get_ip(struct kvm_vcpu *vcpu)
return kvm_rip_read(vcpu);
}
+unsigned long kvm_arch_vcpu_get_frame_pointer(struct kvm_vcpu *vcpu)
+{
+ return kvm_register_read_raw(vcpu, VCPU_REGS_RBP);
+}
+
+bool kvm_arch_vcpu_read_virt(struct kvm_vcpu *vcpu, void *addr, void *dest, unsigned int length)
+{
+ struct x86_exception e;
+
+ /* Return true on success */
+ return kvm_read_guest_virt(vcpu, addr, dest, length, &e) == X86EMUL_CONTINUE;
+}
+
+bool kvm_arch_vcpu_is_64bit(struct kvm_vcpu *vcpu)
+{
+ return is_64_bit_mode(vcpu);
+}
+
int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu)
{
return kvm_vcpu_exiting_guest_mode(vcpu) == IN_GUEST_MODE;
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index fb6c6109f..f92f1a9c8 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -1595,6 +1595,10 @@ static inline bool kvm_arch_intc_initialized(struct kvm *kvm)
#ifdef CONFIG_GUEST_PERF_EVENTS
unsigned long kvm_arch_vcpu_get_ip(struct kvm_vcpu *vcpu);
+unsigned long kvm_arch_vcpu_get_frame_pointer(struct kvm_vcpu *vcpu);
+bool kvm_arch_vcpu_read_virt(struct kvm_vcpu *vcpu, void *addr, void *dest,
+ unsigned int length);
+bool kvm_arch_vcpu_is_64bit(struct kvm_vcpu *vcpu);
void kvm_register_perf_callbacks(unsigned int (*pt_intr_handler)(void));
void kvm_unregister_perf_callbacks(void);
--
2.42.0> All warnings (new ones prefixed by >>):
>
> arch/x86/kvm/x86.c: In function 'kvm_arch_vcpu_read_virt':
> >> arch/x86/kvm/x86.c:12917:42: warning: passing argument 2 of 'kvm_read_guest_virt' makes integer from pointer without a cast [-Wint-conversion]
> 12917 | return kvm_read_guest_virt(vcpu, addr, dest, length, &e) == X86EMUL_CONTINUE;
> | ^~~~
> | |
> | void *
> arch/x86/kvm/x86.c:7388:38: note: expected 'gva_t' {aka 'long unsigned int'} but argument is of type 'void *'
> 7388 | gva_t addr, void *val, unsigned int bytes,
> | ~~~~~~^~~~
>
Terribly sorry for the build warnings, which is caused by type casting.
Will be fixed in the next version.
Hi Tianyi,
kernel test robot noticed the following build errors:
[auto build test ERROR on 8a749fd1a8720d4619c91c8b6e7528c0a355c0aa]
url: https://github.com/intel-lab-lkp/linux/commits/Tianyi-Liu/KVM-Add-arch-specific-interfaces-for-sampling-guest-callchains/20231008-230042
base: 8a749fd1a8720d4619c91c8b6e7528c0a355c0aa
patch link: https://lore.kernel.org/r/SY4P282MB10840154D4F09917D6528BC69DCFA%40SY4P282MB1084.AUSP282.PROD.OUTLOOK.COM
patch subject: [PATCH v2 1/5] KVM: Add arch specific interfaces for sampling guest callchains
config: x86_64-rhel-8.3-rust (https://download.01.org/0day-ci/archive/20231009/202310090652.6TMWiCuU-lkp@intel.com/config)
compiler: clang version 16.0.4 (https://github.com/llvm/llvm-project.git ae42196bc493ffe877a7e3dff8be32035dea4d07)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231009/202310090652.6TMWiCuU-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/202310090652.6TMWiCuU-lkp@intel.com/
All errors (new ones prefixed by >>):
>> arch/x86/kvm/x86.c:12917:35: error: incompatible pointer to integer conversion passing 'void *' to parameter of type 'gva_t' (aka 'unsigned long') [-Wint-conversion]
return kvm_read_guest_virt(vcpu, addr, dest, length, &e) == X86EMUL_CONTINUE;
^~~~
arch/x86/kvm/x86.c:7403:19: note: passing argument to parameter here
EXPORT_SYMBOL_GPL(kvm_read_guest_virt);
^
1 error generated.
vim +12917 arch/x86/kvm/x86.c
12911
12912 bool kvm_arch_vcpu_read_virt(struct kvm_vcpu *vcpu, void *addr, void *dest, unsigned int length)
12913 {
12914 struct x86_exception e;
12915
12916 /* Return true on success */
12917 return kvm_read_guest_virt(vcpu, addr, dest, length, &e) == X86EMUL_CONTINUE;
12918 }
12919
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
Hi Tianyi,
kernel test robot noticed the following build warnings:
[auto build test WARNING on 8a749fd1a8720d4619c91c8b6e7528c0a355c0aa]
url: https://github.com/intel-lab-lkp/linux/commits/Tianyi-Liu/KVM-Add-arch-specific-interfaces-for-sampling-guest-callchains/20231008-230042
base: 8a749fd1a8720d4619c91c8b6e7528c0a355c0aa
patch link: https://lore.kernel.org/r/SY4P282MB10840154D4F09917D6528BC69DCFA%40SY4P282MB1084.AUSP282.PROD.OUTLOOK.COM
patch subject: [PATCH v2 1/5] KVM: Add arch specific interfaces for sampling guest callchains
config: x86_64-defconfig (https://download.01.org/0day-ci/archive/20231009/202310090559.wzrojQni-lkp@intel.com/config)
compiler: gcc-11 (Debian 11.3.0-12) 11.3.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231009/202310090559.wzrojQni-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/202310090559.wzrojQni-lkp@intel.com/
All warnings (new ones prefixed by >>):
arch/x86/kvm/x86.c: In function 'kvm_arch_vcpu_read_virt':
>> arch/x86/kvm/x86.c:12917:42: warning: passing argument 2 of 'kvm_read_guest_virt' makes integer from pointer without a cast [-Wint-conversion]
12917 | return kvm_read_guest_virt(vcpu, addr, dest, length, &e) == X86EMUL_CONTINUE;
| ^~~~
| |
| void *
arch/x86/kvm/x86.c:7388:38: note: expected 'gva_t' {aka 'long unsigned int'} but argument is of type 'void *'
7388 | gva_t addr, void *val, unsigned int bytes,
| ~~~~~~^~~~
vim +/kvm_read_guest_virt +12917 arch/x86/kvm/x86.c
12911
12912 bool kvm_arch_vcpu_read_virt(struct kvm_vcpu *vcpu, void *addr, void *dest, unsigned int length)
12913 {
12914 struct x86_exception e;
12915
12916 /* Return true on success */
12917 return kvm_read_guest_virt(vcpu, addr, dest, length, &e) == X86EMUL_CONTINUE;
12918 }
12919
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
Hi Tianyi,
kernel test robot noticed the following build warnings:
[auto build test WARNING on 8a749fd1a8720d4619c91c8b6e7528c0a355c0aa]
url: https://github.com/intel-lab-lkp/linux/commits/Tianyi-Liu/KVM-Add-arch-specific-interfaces-for-sampling-guest-callchains/20231008-230042
base: 8a749fd1a8720d4619c91c8b6e7528c0a355c0aa
patch link: https://lore.kernel.org/r/SY4P282MB10840154D4F09917D6528BC69DCFA%40SY4P282MB1084.AUSP282.PROD.OUTLOOK.COM
patch subject: [PATCH v2 1/5] KVM: Add arch specific interfaces for sampling guest callchains
config: arm64-randconfig-003-20231009 (https://download.01.org/0day-ci/archive/20231009/202310090448.ffbVfkHi-lkp@intel.com/config)
compiler: aarch64-linux-gcc (GCC) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231009/202310090448.ffbVfkHi-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/202310090448.ffbVfkHi-lkp@intel.com/
All warnings (new ones prefixed by >>):
In file included from include/uapi/linux/posix_types.h:5,
from include/uapi/linux/types.h:14,
from include/linux/types.h:6,
from include/linux/kasan-checks.h:5,
from include/asm-generic/rwonce.h:26,
from arch/arm64/include/asm/rwonce.h:71,
from include/linux/compiler.h:246,
from include/asm-generic/bug.h:5,
from arch/arm64/include/asm/bug.h:26,
from include/linux/bug.h:5,
from arch/arm64/kvm/arm.c:7:
arch/arm64/kvm/arm.c: In function 'kvm_arch_vcpu_get_frame_pointer':
>> include/linux/stddef.h:8:14: warning: returning 'void *' from a function with return type 'long unsigned int' makes integer from pointer without a cast [-Wint-conversion]
8 | #define NULL ((void *)0)
| ^
arch/arm64/kvm/arm.c:578:16: note: in expansion of macro 'NULL'
578 | return NULL;
| ^~~~
vim +8 include/linux/stddef.h
^1da177e4c3f41 Linus Torvalds 2005-04-16 6
^1da177e4c3f41 Linus Torvalds 2005-04-16 7 #undef NULL
^1da177e4c3f41 Linus Torvalds 2005-04-16 @8 #define NULL ((void *)0)
6e218287432472 Richard Knutsson 2006-09-30 9
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
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