From: eillon <yezhenyu2@huawei.com> hulk inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/IB103D CVE: NA ---------------------------------------------------------------------- Updating the dirty bitmap based on the HDBSS buffer. Similar to the implementation of the x86 pml feature, KVM flushes the buffers on all VM-Exits, thus we only need to kick running vCPUs to force a VM-Exit. Signed-off-by: eillon <yezhenyu2@huawei.com> --- arch/arm64/kvm/arm.c | 10 ++++++++ arch/arm64/kvm/handle_exit.c | 47 ++++++++++++++++++++++++++++++++++++ arch/arm64/kvm/mmu.c | 10 +++++++- 3 files changed, 66 insertions(+), 1 deletion(-) diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index d72c6c72e60a..f7206ab91c9c 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -1837,7 +1837,17 @@ long kvm_arch_vcpu_ioctl(struct file *filp, void kvm_arch_sync_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot) { + /* + * Flush all CPUs' dirty log buffers to the dirty_bitmap. Called + * before reporting dirty_bitmap to userspace. KVM flushes the buffers + * on all VM-Exits, thus we only need to kick running vCPUs to force a + * VM-Exit. + */ + struct kvm_vcpu *vcpu; + unsigned long i; + kvm_for_each_vcpu(i, vcpu, kvm) + kvm_vcpu_kick(vcpu); } static int kvm_vm_ioctl_set_device_addr(struct kvm *kvm, diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c index 90959b8b6228..c9b3ce381018 100644 --- a/arch/arm64/kvm/handle_exit.c +++ b/arch/arm64/kvm/handle_exit.c @@ -292,6 +292,50 @@ static exit_handle_fn kvm_get_exit_handler(struct kvm_vcpu *vcpu) return arm_exit_handlers[esr_ec]; } +#define HDBSS_ENTRY_VALID_SHIFT 0 +#define HDBSS_ENTRY_VALID_MASK (1UL << HDBSS_ENTRY_VALID_SHIFT) +#define HDBSS_ENTRY_IPA_SHIFT 12 +#define HDBSS_ENTRY_IPA_MASK GENMASK_ULL(55, HDBSS_ENTRY_IPA_SHIFT) + +static void kvm_flush_hdbss_buffer(struct kvm_vcpu *vcpu) +{ + int idx, curr_idx; + u64 *hdbss_buf; + + if (!vcpu->kvm->enable_hdbss) + return; + + dsb(sy); + isb(); + curr_idx = HDBSSPROD_IDX(read_sysreg_s(SYS_HDBSSPROD_EL2)); + + /* Do nothing if HDBSS buffer is empty or br_el2 is NULL */ + if (curr_idx == 0 || vcpu->arch.hdbss.br_el2 == 0) + return; + + hdbss_buf = page_address(phys_to_page(HDBSSBR_BADDR(vcpu->arch.hdbss.br_el2))); + if (!hdbss_buf) { + kvm_err("Enter flush hdbss buffer with buffer == NULL!"); + return; + } + + for (idx = 0; idx < curr_idx; idx++) { + u64 gpa; + + gpa = hdbss_buf[idx]; + if (!(gpa & HDBSS_ENTRY_VALID_MASK)) + continue; + + gpa = gpa & HDBSS_ENTRY_IPA_MASK; + kvm_vcpu_mark_page_dirty(vcpu, gpa >> PAGE_SHIFT); + } + + /* reset HDBSS index */ + write_sysreg_s(0, SYS_HDBSSPROD_EL2); + dsb(sy); + isb(); +} + /* * We may be single-stepping an emulated instruction. If the emulation * has been completed in the kernel, we can return to userspace with a @@ -327,6 +371,9 @@ int handle_exit(struct kvm_vcpu *vcpu, int exception_index) { struct kvm_run *run = vcpu->run; + if (vcpu->kvm->enable_hdbss) + kvm_flush_hdbss_buffer(vcpu); + if (ARM_SERROR_PENDING(exception_index)) { /* * The SError is handled by handle_exit_early(). If the guest diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index ea7ab43154cc..0347ab14cf11 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -1660,7 +1660,7 @@ int kvm_handle_guest_abort(struct kvm_vcpu *vcpu) unsigned long fault_status; phys_addr_t fault_ipa; struct kvm_memory_slot *memslot; - unsigned long hva; + unsigned long hva, iss2; bool is_iabt, write_fault, writable; gfn_t gfn; int ret, idx; @@ -1670,6 +1670,14 @@ int kvm_handle_guest_abort(struct kvm_vcpu *vcpu) fault_ipa = kvm_vcpu_get_fault_ipa(vcpu); is_iabt = kvm_vcpu_trap_is_iabt(vcpu); + /* + * HDBSS buffer already flushed when enter handle_trap_exceptions(). + * Nothing to do here. + */ + iss2 = ESR_ELx_ISS2(kvm_vcpu_get_esr(vcpu)); + if (fault_status == ESR_ELx_FSC_PERM && (iss2 & ESR_ELx_HDBSSF)) + return 1; + if (fault_status == ESR_ELx_FSC_FAULT) { /* Beyond sanitised PARange (which is the IPA limit) */ if (fault_ipa >= BIT_ULL(get_kvm_ipa_limit())) { -- 2.39.3