| Message ID | 20230421165305.804301-8-vipinsh@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: arm64: Use MMU read lock for clearing dirty logs | expand |
Hi Vipin,
kernel test robot noticed the following build warnings:
[auto build test WARNING on 95b9779c1758f03cf494e8550d6249a40089ed1c]
url: https://github.com/intel-lab-lkp/linux/commits/Vipin-Sharma/KVM-selftests-Allow-dirty_log_perf_test-to-clear-dirty-memory-in-chunks/20230422-005708
base: 95b9779c1758f03cf494e8550d6249a40089ed1c
patch link: https://lore.kernel.org/r/20230421165305.804301-8-vipinsh%40google.com
patch subject: [PATCH 7/9] KVM: mmu: Move mmu lock/unlock to arch code for clear dirty log
config: riscv-allyesconfig (https://download.01.org/0day-ci/archive/20230422/202304220315.bpwbgH5n-lkp@intel.com/config)
compiler: riscv64-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/e7505b53d53e3bb5e7f1c43233ef3644673edb75
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Vipin-Sharma/KVM-selftests-Allow-dirty_log_perf_test-to-clear-dirty-memory-in-chunks/20230422-005708
git checkout e7505b53d53e3bb5e7f1c43233ef3644673edb75
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=riscv olddefconfig
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=riscv SHELL=/bin/bash arch/riscv/kvm/
If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
| Link: https://lore.kernel.org/oe-kbuild-all/202304220315.bpwbgH5n-lkp@intel.com/
All warnings (new ones prefixed by >>):
arch/riscv/kvm/mmu.c: In function 'kvm_arch_mmu_enable_log_dirty_pt_masked':
>> arch/riscv/kvm/mmu.c:399:9: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
399 | phys_addr_t base_gfn = slot->base_gfn + gfn_offset;
| ^~~~~~~~~~~
vim +399 arch/riscv/kvm/mmu.c
c9d57373fc87a3 Anup Patel 2022-07-29 392
9d05c1fee83757 Anup Patel 2021-09-27 393 void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm,
9d05c1fee83757 Anup Patel 2021-09-27 394 struct kvm_memory_slot *slot,
9d05c1fee83757 Anup Patel 2021-09-27 395 gfn_t gfn_offset,
9d05c1fee83757 Anup Patel 2021-09-27 396 unsigned long mask)
9d05c1fee83757 Anup Patel 2021-09-27 397 {
e7505b53d53e3b Vipin Sharma 2023-04-21 398 spin_lock(&kvm->mmu_lock);
9d05c1fee83757 Anup Patel 2021-09-27 @399 phys_addr_t base_gfn = slot->base_gfn + gfn_offset;
9d05c1fee83757 Anup Patel 2021-09-27 400 phys_addr_t start = (base_gfn + __ffs(mask)) << PAGE_SHIFT;
9d05c1fee83757 Anup Patel 2021-09-27 401 phys_addr_t end = (base_gfn + __fls(mask) + 1) << PAGE_SHIFT;
9d05c1fee83757 Anup Patel 2021-09-27 402
26708234eb12e7 Anup Patel 2022-05-09 403 gstage_wp_range(kvm, start, end);
e7505b53d53e3b Vipin Sharma 2023-04-21 404 spin_unlock(&kvm->mmu_lock);
9d05c1fee83757 Anup Patel 2021-09-27 405 }
99cdc6c18c2d81 Anup Patel 2021-09-27 406
On Fri, Apr 21, 2023 at 12:43 PM kernel test robot <lkp@intel.com> wrote: > > Hi Vipin, > > All warnings (new ones prefixed by >>): > > arch/riscv/kvm/mmu.c: In function 'kvm_arch_mmu_enable_log_dirty_pt_masked': > >> arch/riscv/kvm/mmu.c:399:9: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement] > 399 | phys_addr_t base_gfn = slot->base_gfn + gfn_offset; > | ^~~~~~~~~~~ > > I will fix it in v2.
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index 7113587222ff..dc1c9059604e 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -1002,7 +1002,9 @@ void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm, struct kvm_memory_slot *slot, gfn_t gfn_offset, unsigned long mask) { + write_lock(&kvm->mmu_lock); kvm_mmu_write_protect_pt_masked(kvm, slot, gfn_offset, mask); + write_unlock(&kvm->mmu_lock); } static void kvm_send_hwpoison_signal(unsigned long address, short lsb) diff --git a/arch/mips/kvm/mmu.c b/arch/mips/kvm/mmu.c index e8c08988ed37..b8d4723d197e 100644 --- a/arch/mips/kvm/mmu.c +++ b/arch/mips/kvm/mmu.c @@ -415,11 +415,13 @@ void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm, struct kvm_memory_slot *slot, gfn_t gfn_offset, unsigned long mask) { + spin_lock(&kvm->mmu_lock); gfn_t base_gfn = slot->base_gfn + gfn_offset; gfn_t start = base_gfn + __ffs(mask); gfn_t end = base_gfn + __fls(mask); kvm_mips_mkclean_gpa_pt(kvm, start, end); + spin_unlock(&kvm->mmu_lock); } /* diff --git a/arch/riscv/kvm/mmu.c b/arch/riscv/kvm/mmu.c index 78211aed36fa..425fa11dcf9c 100644 --- a/arch/riscv/kvm/mmu.c +++ b/arch/riscv/kvm/mmu.c @@ -395,11 +395,13 @@ void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm, gfn_t gfn_offset, unsigned long mask) { + spin_lock(&kvm->mmu_lock); phys_addr_t base_gfn = slot->base_gfn + gfn_offset; phys_addr_t start = (base_gfn + __ffs(mask)) << PAGE_SHIFT; phys_addr_t end = (base_gfn + __fls(mask) + 1) << PAGE_SHIFT; gstage_wp_range(kvm, start, end); + spin_unlock(&kvm->mmu_lock); } void kvm_arch_sync_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 144c5a01cd77..f1dc549b01cb 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -1367,6 +1367,7 @@ void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm, struct kvm_memory_slot *slot, gfn_t gfn_offset, unsigned long mask) { + write_lock(&kvm->mmu_lock); /* * Huge pages are NOT write protected when we start dirty logging in * initially-all-set mode; must write protect them here so that they @@ -1397,6 +1398,8 @@ void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm, kvm_mmu_clear_dirty_pt_masked(kvm, slot, gfn_offset, mask); else kvm_mmu_write_protect_pt_masked(kvm, slot, gfn_offset, mask); + + write_unlock(&kvm->mmu_lock); } int kvm_cpu_dirty_log_size(void) diff --git a/virt/kvm/dirty_ring.c b/virt/kvm/dirty_ring.c index c1cd7dfe4a90..d894c58d2152 100644 --- a/virt/kvm/dirty_ring.c +++ b/virt/kvm/dirty_ring.c @@ -66,9 +66,7 @@ static void kvm_reset_dirty_gfn(struct kvm *kvm, u32 slot, u64 offset, u64 mask) if (!memslot || (offset + __fls(mask)) >= memslot->npages) return; - KVM_MMU_LOCK(kvm); kvm_arch_mmu_enable_log_dirty_pt_masked(kvm, memslot, offset, mask); - KVM_MMU_UNLOCK(kvm); } int kvm_dirty_ring_alloc(struct kvm_dirty_ring *ring, int index, u32 size) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index f40b72eb0e7b..378c40e958b6 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -2157,7 +2157,6 @@ static int kvm_get_dirty_log_protect(struct kvm *kvm, struct kvm_dirty_log *log) dirty_bitmap_buffer = kvm_second_dirty_bitmap(memslot); memset(dirty_bitmap_buffer, 0, n); - KVM_MMU_LOCK(kvm); for (i = 0; i < n / sizeof(long); i++) { unsigned long mask; gfn_t offset; @@ -2173,7 +2172,6 @@ static int kvm_get_dirty_log_protect(struct kvm *kvm, struct kvm_dirty_log *log) kvm_arch_mmu_enable_log_dirty_pt_masked(kvm, memslot, offset, mask); } - KVM_MMU_UNLOCK(kvm); } if (flush) @@ -2268,7 +2266,6 @@ static int kvm_clear_dirty_log_protect(struct kvm *kvm, if (copy_from_user(dirty_bitmap_buffer, log->dirty_bitmap, n)) return -EFAULT; - KVM_MMU_LOCK(kvm); for (offset = log->first_page, i = offset / BITS_PER_LONG, n = DIV_ROUND_UP(log->num_pages, BITS_PER_LONG); n--; i++, offset += BITS_PER_LONG) { @@ -2291,7 +2288,6 @@ static int kvm_clear_dirty_log_protect(struct kvm *kvm, offset, mask); } } - KVM_MMU_UNLOCK(kvm); if (flush) kvm_arch_flush_remote_tlbs_memslot(kvm, memslot);
Move mmu_lock lock and unlock calls from common code in kvm_clear_dirty_log_protect() to arch specific code in kvm_arch_mmu_enable_log_dirty_pt_masked(). None of the other code inside the for loop of kvm_arch_mmu_enable_log_dirty_pt_masked() needs mmu_lock exclusivity apart from the arch specific API call. Future commits will change clear dirty log operations under mmu read lock instead of write lock for ARM and, potentially, x86 architectures. No functional changes intended. Signed-off-by: Vipin Sharma <vipinsh@google.com> --- arch/arm64/kvm/mmu.c | 2 ++ arch/mips/kvm/mmu.c | 2 ++ arch/riscv/kvm/mmu.c | 2 ++ arch/x86/kvm/mmu/mmu.c | 3 +++ virt/kvm/dirty_ring.c | 2 -- virt/kvm/kvm_main.c | 4 ---- 6 files changed, 9 insertions(+), 6 deletions(-)