| Message ID | 20230731162201.271114-16-xiaoyao.li@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | QEMU gmem implemention | expand |
On Mon, Jul 31, 2023 at 12:21:57PM -0400, Xiaoyao Li <xiaoyao.li@intel.com> wrote: > From: Chao Peng <chao.p.peng@linux.intel.com> > > Currently only KVM_MEMORY_EXIT_FLAG_PRIVATE in flags is valid when > KVM_EXIT_MEMORY_FAULT happens. It indicates userspace needs to do > the memory conversion on the RAMBlock to turn the memory into desired > attribute, i.e., private/shared. > > Note, KVM_EXIT_MEMORY_FAULT makes sense only when the RAMBlock has > gmem memory backend. > > Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com> > Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com> > --- > accel/kvm/kvm-all.c | 52 +++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 52 insertions(+) > > diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c > index f9b5050b8885..72d50b923bf2 100644 > --- a/accel/kvm/kvm-all.c > +++ b/accel/kvm/kvm-all.c > @@ -3040,6 +3040,48 @@ static void kvm_eat_signals(CPUState *cpu) > } while (sigismember(&chkset, SIG_IPI)); > } > > +static int kvm_convert_memory(hwaddr start, hwaddr size, bool to_private) > +{ > + MemoryRegionSection section; > + void *addr; > + RAMBlock *rb; > + ram_addr_t offset; > + int ret = -1; > + > + section = memory_region_find(get_system_memory(), start, size); > + if (!section.mr) { > + return ret; > + } > + > + if (memory_region_can_be_private(section.mr)) { > + if (to_private) { > + ret = kvm_set_memory_attributes_private(start, size); > + } else { > + ret = kvm_set_memory_attributes_shared(start, size); > + } > + > + if (ret) { > + return ret; > + } > + > + addr = memory_region_get_ram_ptr(section.mr) + > + section.offset_within_region; > + rb = qemu_ram_block_from_host(addr, false, &offset); Here we have already section. section.mr->ram_block. We don't have to scan the existing RAMBlocks. Except that, looks good to me. Reviewed-by: Isaku Yamahata <isaku.yamahata@intel.com>
On 2023-07-31 at 12:21:57 -0400, Xiaoyao Li wrote: > From: Chao Peng <chao.p.peng@linux.intel.com> > > Currently only KVM_MEMORY_EXIT_FLAG_PRIVATE in flags is valid when > KVM_EXIT_MEMORY_FAULT happens. It indicates userspace needs to do > the memory conversion on the RAMBlock to turn the memory into desired > attribute, i.e., private/shared. > > Note, KVM_EXIT_MEMORY_FAULT makes sense only when the RAMBlock has > gmem memory backend. > > Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com> > Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com> > --- > accel/kvm/kvm-all.c | 52 +++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 52 insertions(+) > > diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c > index f9b5050b8885..72d50b923bf2 100644 > --- a/accel/kvm/kvm-all.c > +++ b/accel/kvm/kvm-all.c > @@ -3040,6 +3040,48 @@ static void kvm_eat_signals(CPUState *cpu) > } while (sigismember(&chkset, SIG_IPI)); > } > > +static int kvm_convert_memory(hwaddr start, hwaddr size, bool to_private) > +{ > + MemoryRegionSection section; > + void *addr; > + RAMBlock *rb; > + ram_addr_t offset; > + int ret = -1; > + > + section = memory_region_find(get_system_memory(), start, size); > + if (!section.mr) { > + return ret; > + } > + > + if (memory_region_can_be_private(section.mr)) { > + if (to_private) { > + ret = kvm_set_memory_attributes_private(start, size); > + } else { > + ret = kvm_set_memory_attributes_shared(start, size); > + } > + > + if (ret) { > + return ret; Should we unref the memory region before return? Thanks, Yilun > + } > + > + addr = memory_region_get_ram_ptr(section.mr) + > + section.offset_within_region; > + rb = qemu_ram_block_from_host(addr, false, &offset); > + /* > + * With KVM_SET_MEMORY_ATTRIBUTES by kvm_set_memory_attributes(), > + * operation on underlying file descriptor is only for releasing > + * unnecessary pages. > + */ > + ram_block_convert_range(rb, offset, size, to_private); > + } else { > + warn_report("Convert non guest-memfd backed memory region (0x%"HWADDR_PRIx" ,+ 0x%"HWADDR_PRIx") to %s", > + start, size, to_private ? "private" : "shared"); > + } > + > + memory_region_unref(section.mr); > + return ret; > +}
On 8/3/2023 6:25 AM, Isaku Yamahata wrote: > On Mon, Jul 31, 2023 at 12:21:57PM -0400, > Xiaoyao Li <xiaoyao.li@intel.com> wrote: > >> From: Chao Peng <chao.p.peng@linux.intel.com> >> >> Currently only KVM_MEMORY_EXIT_FLAG_PRIVATE in flags is valid when >> KVM_EXIT_MEMORY_FAULT happens. It indicates userspace needs to do >> the memory conversion on the RAMBlock to turn the memory into desired >> attribute, i.e., private/shared. >> >> Note, KVM_EXIT_MEMORY_FAULT makes sense only when the RAMBlock has >> gmem memory backend. >> >> Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com> >> Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com> >> --- >> accel/kvm/kvm-all.c | 52 +++++++++++++++++++++++++++++++++++++++++++++ >> 1 file changed, 52 insertions(+) >> >> diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c >> index f9b5050b8885..72d50b923bf2 100644 >> --- a/accel/kvm/kvm-all.c >> +++ b/accel/kvm/kvm-all.c >> @@ -3040,6 +3040,48 @@ static void kvm_eat_signals(CPUState *cpu) >> } while (sigismember(&chkset, SIG_IPI)); >> } >> >> +static int kvm_convert_memory(hwaddr start, hwaddr size, bool to_private) >> +{ >> + MemoryRegionSection section; >> + void *addr; >> + RAMBlock *rb; >> + ram_addr_t offset; >> + int ret = -1; >> + >> + section = memory_region_find(get_system_memory(), start, size); >> + if (!section.mr) { >> + return ret; >> + } >> + >> + if (memory_region_can_be_private(section.mr)) { >> + if (to_private) { >> + ret = kvm_set_memory_attributes_private(start, size); >> + } else { >> + ret = kvm_set_memory_attributes_shared(start, size); >> + } >> + >> + if (ret) { >> + return ret; >> + } >> + >> + addr = memory_region_get_ram_ptr(section.mr) + >> + section.offset_within_region; >> + rb = qemu_ram_block_from_host(addr, false, &offset); > > Here we have already section. section.mr->ram_block. We don't have to > scan the existing RAMBlocks. But we don't have the @offset, do we? > Except that, looks good to me. > Reviewed-by: Isaku Yamahata <isaku.yamahata@intel.com>
On 8/9/2023 11:02 PM, Xu Yilun wrote: > On 2023-07-31 at 12:21:57 -0400, Xiaoyao Li wrote: >> From: Chao Peng <chao.p.peng@linux.intel.com> >> >> Currently only KVM_MEMORY_EXIT_FLAG_PRIVATE in flags is valid when >> KVM_EXIT_MEMORY_FAULT happens. It indicates userspace needs to do >> the memory conversion on the RAMBlock to turn the memory into desired >> attribute, i.e., private/shared. >> >> Note, KVM_EXIT_MEMORY_FAULT makes sense only when the RAMBlock has >> gmem memory backend. >> >> Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com> >> Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com> >> --- >> accel/kvm/kvm-all.c | 52 +++++++++++++++++++++++++++++++++++++++++++++ >> 1 file changed, 52 insertions(+) >> >> diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c >> index f9b5050b8885..72d50b923bf2 100644 >> --- a/accel/kvm/kvm-all.c >> +++ b/accel/kvm/kvm-all.c >> @@ -3040,6 +3040,48 @@ static void kvm_eat_signals(CPUState *cpu) >> } while (sigismember(&chkset, SIG_IPI)); >> } >> >> +static int kvm_convert_memory(hwaddr start, hwaddr size, bool to_private) >> +{ >> + MemoryRegionSection section; >> + void *addr; >> + RAMBlock *rb; >> + ram_addr_t offset; >> + int ret = -1; >> + >> + section = memory_region_find(get_system_memory(), start, size); >> + if (!section.mr) { >> + return ret; >> + } >> + >> + if (memory_region_can_be_private(section.mr)) { >> + if (to_private) { >> + ret = kvm_set_memory_attributes_private(start, size); >> + } else { >> + ret = kvm_set_memory_attributes_shared(start, size); >> + } >> + >> + if (ret) { >> + return ret; > > Should we unref the memory region before return? Thanks for catching this! > Thanks, > Yilun > >> + } >> + >> + addr = memory_region_get_ram_ptr(section.mr) + >> + section.offset_within_region; >> + rb = qemu_ram_block_from_host(addr, false, &offset); >> + /* >> + * With KVM_SET_MEMORY_ATTRIBUTES by kvm_set_memory_attributes(), >> + * operation on underlying file descriptor is only for releasing >> + * unnecessary pages. >> + */ >> + ram_block_convert_range(rb, offset, size, to_private); >> + } else { >> + warn_report("Convert non guest-memfd backed memory region (0x%"HWADDR_PRIx" ,+ 0x%"HWADDR_PRIx") to %s", >> + start, size, to_private ? "private" : "shared"); >> + } >> + >> + memory_region_unref(section.mr); >> + return ret; >> +}
diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c index f9b5050b8885..72d50b923bf2 100644 --- a/accel/kvm/kvm-all.c +++ b/accel/kvm/kvm-all.c @@ -3040,6 +3040,48 @@ static void kvm_eat_signals(CPUState *cpu) } while (sigismember(&chkset, SIG_IPI)); } +static int kvm_convert_memory(hwaddr start, hwaddr size, bool to_private) +{ + MemoryRegionSection section; + void *addr; + RAMBlock *rb; + ram_addr_t offset; + int ret = -1; + + section = memory_region_find(get_system_memory(), start, size); + if (!section.mr) { + return ret; + } + + if (memory_region_can_be_private(section.mr)) { + if (to_private) { + ret = kvm_set_memory_attributes_private(start, size); + } else { + ret = kvm_set_memory_attributes_shared(start, size); + } + + if (ret) { + return ret; + } + + addr = memory_region_get_ram_ptr(section.mr) + + section.offset_within_region; + rb = qemu_ram_block_from_host(addr, false, &offset); + /* + * With KVM_SET_MEMORY_ATTRIBUTES by kvm_set_memory_attributes(), + * operation on underlying file descriptor is only for releasing + * unnecessary pages. + */ + ram_block_convert_range(rb, offset, size, to_private); + } else { + warn_report("Convert non guest-memfd backed memory region (0x%"HWADDR_PRIx" ,+ 0x%"HWADDR_PRIx") to %s", + start, size, to_private ? "private" : "shared"); + } + + memory_region_unref(section.mr); + return ret; +} + int kvm_cpu_exec(CPUState *cpu) { struct kvm_run *run = cpu->kvm_run; @@ -3198,6 +3240,16 @@ int kvm_cpu_exec(CPUState *cpu) break; } break; + case KVM_EXIT_MEMORY_FAULT: + if (run->memory.flags & ~KVM_MEMORY_EXIT_FLAG_PRIVATE) { + error_report("KVM_EXIT_MEMORY_FAULT: Unknown flag 0x%" PRIx64, + (uint64_t)run->memory.flags); + ret = -1; + break; + } + ret = kvm_convert_memory(run->memory.gpa, run->memory.size, + run->memory.flags & KVM_MEMORY_EXIT_FLAG_PRIVATE); + break; default: DPRINTF("kvm_arch_handle_exit\n"); ret = kvm_arch_handle_exit(cpu, run);