This enables the ring-based dirty memory tracking on ARM64. The
feature is configured by CONFIG_HAVE_KVM_DIRTY_RING, detected and
enabled by KVM_CAP_DIRTY_LOG_RING. A ring buffer is created on every
VCPU when the feature is enabled. Each entry in the ring buffer is
described by 'struct kvm_dirty_gfn'.
A ring buffer entry is pushed when a page becomes dirty on host,
and pulled by userspace after the ring buffer is mapped at physical
page offset KVM_DIRTY_LOG_PAGE_OFFSET. The specific VCPU is enforced
to exit if its ring buffer becomes softly full. Besides, the ring
buffer can be reset by ioctl command KVM_RESET_DIRTY_RINGS to release
those pulled ring buffer entries.
Signed-off-by: Gavin Shan <gshan@redhat.com>
---
Documentation/virt/kvm/api.rst | 2 +-
arch/arm64/include/uapi/asm/kvm.h | 1 +
arch/arm64/kvm/Kconfig | 1 +
arch/arm64/kvm/arm.c | 8 ++++++++
4 files changed, 11 insertions(+), 1 deletion(-)
diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index abd7c32126ce..19fa1ac017ed 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -8022,7 +8022,7 @@ regardless of what has actually been exposed through the CPUID leaf.
8.29 KVM_CAP_DIRTY_LOG_RING
---------------------------
-:Architectures: x86
+:Architectures: x86, arm64
:Parameters: args[0] - size of the dirty log ring
KVM is capable of tracking dirty memory using ring buffers that are
diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h
index 316917b98707..a7a857f1784d 100644
--- a/arch/arm64/include/uapi/asm/kvm.h
+++ b/arch/arm64/include/uapi/asm/kvm.h
@@ -43,6 +43,7 @@
#define __KVM_HAVE_VCPU_EVENTS
#define KVM_COALESCED_MMIO_PAGE_OFFSET 1
+#define KVM_DIRTY_LOG_PAGE_OFFSET 64
#define KVM_REG_SIZE(id) \
(1U << (((id) & KVM_REG_SIZE_MASK) >> KVM_REG_SIZE_SHIFT))
diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig
index 815cc118c675..0309b2d0f2da 100644
--- a/arch/arm64/kvm/Kconfig
+++ b/arch/arm64/kvm/Kconfig
@@ -32,6 +32,7 @@ menuconfig KVM
select KVM_VFIO
select HAVE_KVM_EVENTFD
select HAVE_KVM_IRQFD
+ select HAVE_KVM_DIRTY_RING
select HAVE_KVM_MSI
select HAVE_KVM_IRQCHIP
select HAVE_KVM_IRQ_ROUTING
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 2ff0ef62abad..76816f8e082b 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -747,6 +747,14 @@ static int check_vcpu_requests(struct kvm_vcpu *vcpu)
if (kvm_check_request(KVM_REQ_SUSPEND, vcpu))
return kvm_vcpu_suspend(vcpu);
+
+ if (kvm_check_request(KVM_REQ_RING_SOFT_FULL, vcpu) &&
+ kvm_dirty_ring_soft_full(&vcpu->dirty_ring)) {
+ kvm_make_request(KVM_REQ_RING_SOFT_FULL, vcpu);
+ vcpu->run->exit_reason = KVM_EXIT_DIRTY_RING_FULL;
+ trace_kvm_dirty_ring_exit(vcpu);
+ return 0;
+ }
}
return 1;
--
2.23.0Hi Gavin,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on kvm/queue]
[also build test WARNING on kvmarm/next linus/master v6.0-rc5 next-20220916]
[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/Gavin-Shan/KVM-arm64-Enable-ring-based-dirty-memory-tracking/20220916-125417
base: https://git.kernel.org/pub/scm/virt/kvm/kvm.git queue
config: arm64-allyesconfig (https://download.01.org/0day-ci/archive/20220918/202209180726.FLL69aKA-lkp@intel.com/config)
compiler: aarch64-linux-gcc (GCC) 12.1.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/intel-lab-lkp/linux/commit/a1a4cd8f6a5e8927f800baff7d965870a1b7d7ba
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Gavin-Shan/KVM-arm64-Enable-ring-based-dirty-memory-tracking/20220916-125417
git checkout a1a4cd8f6a5e8927f800baff7d965870a1b7d7ba
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=arm64 SHELL=/bin/bash
If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@intel.com>
All warnings (new ones prefixed by >>):
>> arch/arm64/kvm/../../../virt/kvm/dirty_ring.c:14:12: warning: no previous prototype for 'kvm_cpu_dirty_log_size' [-Wmissing-prototypes]
14 | int __weak kvm_cpu_dirty_log_size(void)
| ^~~~~~~~~~~~~~~~~~~~~~
vim +/kvm_cpu_dirty_log_size +14 arch/arm64/kvm/../../../virt/kvm/dirty_ring.c
fb04a1eddb1a65 Peter Xu 2020-09-30 13
fb04a1eddb1a65 Peter Xu 2020-09-30 @14 int __weak kvm_cpu_dirty_log_size(void)
fb04a1eddb1a65 Peter Xu 2020-09-30 15 {
fb04a1eddb1a65 Peter Xu 2020-09-30 16 return 0;
fb04a1eddb1a65 Peter Xu 2020-09-30 17 }
fb04a1eddb1a65 Peter Xu 2020-09-30 18
--
0-DAY CI Kernel Test Service
https://01.org/lkp
On 9/18/22 1:10 AM, kernel test robot wrote: > Thank you for the patch! Perhaps something to improve: > > [auto build test WARNING on kvm/queue] > [also build test WARNING on kvmarm/next linus/master v6.0-rc5 next-20220916] > [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/Gavin-Shan/KVM-arm64-Enable-ring-based-dirty-memory-tracking/20220916-125417 > base: https://git.kernel.org/pub/scm/virt/kvm/kvm.git queue > config: arm64-allyesconfig (https://download.01.org/0day-ci/archive/20220918/202209180726.FLL69aKA-lkp@intel.com/config) > compiler: aarch64-linux-gcc (GCC) 12.1.0 > reproduce (this is a W=1 build): > wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross > chmod +x ~/bin/make.cross > # https://github.com/intel-lab-lkp/linux/commit/a1a4cd8f6a5e8927f800baff7d965870a1b7d7ba > git remote add linux-review https://github.com/intel-lab-lkp/linux > git fetch --no-tags linux-review Gavin-Shan/KVM-arm64-Enable-ring-based-dirty-memory-tracking/20220916-125417 > git checkout a1a4cd8f6a5e8927f800baff7d965870a1b7d7ba > # save the config file > mkdir build_dir && cp config build_dir/.config > COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=arm64 SHELL=/bin/bash > > If you fix the issue, kindly add following tag where applicable > Reported-by: kernel test robot <lkp@intel.com> > > All warnings (new ones prefixed by >>): > >>> arch/arm64/kvm/../../../virt/kvm/dirty_ring.c:14:12: warning: no previous prototype for 'kvm_cpu_dirty_log_size' [-Wmissing-prototypes] > 14 | int __weak kvm_cpu_dirty_log_size(void) > | ^~~~~~~~~~~~~~~~~~~~~~ > > [...] Thanks for reporting the issue. The weak function needn't to be overrided by ARM64. In v3, I will have a separate patch to fix the issue by moving its declaration to kvm_dirty_ring.h. Thanks, Gavin
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