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* | | KVM: x86 emulator: simplify emulate_1op()Avi Kivity2011-09-25
| | | | | | | | | | | | | | | | | | | | | | | | emulate_1op() is always called with the same parameters. Simplify by passing just the emulation context. Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* | | KVM: x86 emulator: simplify emulate_2op_cl()Avi Kivity2011-09-25
| | | | | | | | | | | | | | | | | | | | | | | | emulate_2op_cl() is always called with the same parameters. Simplify by passing just the emulation context. Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* | | KVM: x86 emulator: simplify emulate_2op_cl()Avi Kivity2011-09-25
| | | | | | | | | | | | | | | | | | | | | | | | emulate_2op_cl() is always called with the same parameters. Simplify by passing just the emulation context. Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* | | KVM: x86 emulator: simplify emulate_2op_SrcV()Avi Kivity2011-09-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | emulate_2op_SrcV(), and its siblings, emulate_2op_SrcV_nobyte() and emulate_2op_SrcB(), all use the same calling conventions and all get passed exactly the same parameters. Simplify them by passing just the emulation context. Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* | | KVM: APIC: avoid instruction emulation for EOI writesKevin Tian2011-09-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instruction emulation for EOI writes can be skipped, since sane guest simply uses MOV instead of string operations. This is a nice improvement when guest doesn't support x2apic or hyper-V EOI support. a single VM bandwidth is observed with ~8% bandwidth improvement (7.4Gbps->8Gbps), by saving ~5% cycles from EOI emulation. Signed-off-by: Kevin Tian <kevin.tian@intel.com> <Based on earlier work from>: Signed-off-by: Eddie Dong <eddie.dong@intel.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* | | KVM: SVM: Fix TSC MSR read in nested SVMNadav Har'El2011-09-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When the TSC MSR is read by an L2 guest (when L1 allowed this MSR to be read without exit), we need to return L2's notion of the TSC, not L1's. The current code incorrectly returned L1 TSC, because svm_get_msr() was also used in x86.c where this was assumed, but now that these places call the new svm_read_l1_tsc(), the MSR read can be fixed. Signed-off-by: Nadav Har'El <nyh@il.ibm.com> Tested-by: Joerg Roedel <joerg.roedel@amd.com> Acked-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* | | KVM: nVMX: Fix nested VMX TSC emulationNadav Har'El2011-09-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch fixes two corner cases in nested (L2) handling of TSC-related issues: 1. Somewhat suprisingly, according to the Intel spec, if L1 allows WRMSR to the TSC MSR without an exit, then this should set L1's TSC value itself - not offset by vmcs12.TSC_OFFSET (like was wrongly done in the previous code). 2. Allow L1 to disable the TSC_OFFSETING control, and then correctly ignore the vmcs12.TSC_OFFSET. Signed-off-by: Nadav Har'El <nyh@il.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* | | KVM: L1 TSC handlingNadav Har'El2011-09-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | KVM assumed in several places that reading the TSC MSR returns the value for L1. This is incorrect, because when L2 is running, the correct TSC read exit emulation is to return L2's value. We therefore add a new x86_ops function, read_l1_tsc, to use in places that specifically need to read the L1 TSC, NOT the TSC of the current level of guest. Note that one change, of one line in kvm_arch_vcpu_load, is made redundant by a different patch sent by Zachary Amsden (and not yet applied): kvm_arch_vcpu_load() should not read the guest TSC, and if it didn't, of course we didn't have to change the call of kvm_get_msr() to read_l1_tsc(). [avi: moved callback to kvm_x86_ops tsc block] Signed-off-by: Nadav Har'El <nyh@il.ibm.com> Acked-by: Zachary Amsdem <zamsden@gmail.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* | | KVM: MMU: Fix SMEP failure during fetchYang, Wei Y2011-09-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | This patch fix kvm-unit-tests hanging and incorrect PT_ACCESSED_MASK bit set in the case of SMEP fault. The code updated 'eperm' after the variable was checked. Signed-off-by: Yang, Wei <wei.y.yang@intel.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* | | KVM: MMU: Do not unconditionally read PDPTE from guest memoryAvi Kivity2011-09-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Architecturally, PDPTEs are cached in the PDPTRs when CR3 is reloaded. On SVM, it is not possible to implement this, but on VMX this is possible and was indeed implemented until nested SVM changed this to unconditionally read PDPTEs dynamically. This has noticable impact when running PAE guests. Fix by changing the MMU to read PDPTRs from the cache, falling back to reading from memory for the nested MMU. Signed-off-by: Avi Kivity <avi@redhat.com> Tested-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* | | KVM: VMX: trivial: use BUG_ONJulia Lawall2011-09-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use BUG_ON(x) rather than if(x) BUG(); The semantic patch that fixes this problem is as follows: (http://coccinelle.lip6.fr/) // <smpl> @@ identifier x; @@ -if (x) BUG(); +BUG_ON(x); @@ identifier x; @@ -if (!x) BUG(); +BUG_ON(!x); // </smpl> Signed-off-by: Julia Lawall <julia@diku.dk> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* | | KVM: x86: report valid microcode update IDMarcelo Tosatti2011-09-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Windows Server 2008 SP2 checked build with smp > 1 BSOD's during boot due to lack of microcode update: *** Assertion failed: The system BIOS on this machine does not properly support the processor. The system BIOS did not load any microcode update. A BIOS containing the latest microcode update is needed for system reliability. (CurrentUpdateRevision != 0) *** Source File: d:\longhorn\base\hals\update\intelupd\update.c, line 440 Report a non-zero microcode update signature to make it happy. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* | | KVM: x86 emulator: Make x86_decode_insn() return proper macrosTakuya Yoshikawa2011-09-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Return EMULATION_OK/FAILED consistently. Also treat instruction fetch errors, not restricted to X86EMUL_UNHANDLEABLE, as EMULATION_FAILED; although this cannot happen in practice, the current logic will continue the emulation even if the decoder fails to fetch the instruction. Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Signed-off-by: Avi Kivity <avi@redhat.com>
* | | KVM: x86 emulator: Let compiler know insn_fetch() rarely failsTakuya Yoshikawa2011-09-25
| | | | | | | | | | | | | | | | | | | | | | | | Fetching the instruction which was to be executed by the guest cannot fail normally. So compiler should always predict that it will succeed. Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Signed-off-by: Avi Kivity <avi@redhat.com>
* | | KVM: x86 emulator: Drop _size argument from insn_fetch()Takuya Yoshikawa2011-09-25
| | | | | | | | | | | | | | | | | | | | | _type is enough to know the size. Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Signed-off-by: Avi Kivity <avi@redhat.com>
* | | KVM: x86 emulator: Use ctxt->_eip directly in do_insn_fetch_byte()Takuya Yoshikawa2011-09-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of passing ctxt->_eip from insn_fetch() call sites, get it from ctxt in do_insn_fetch_byte(). This is done by replacing the argument _eip of insn_fetch() with _ctxt, which should be better than letting the macro use ctxt silently in its body. Though this changes the place where ctxt->_eip is incremented from insn_fetch() to do_insn_fetch_byte(), this does not have any real effect. Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Signed-off-by: Avi Kivity <avi@redhat.com>
* | | KVM: Intelligent device lookup on I/O busSasha Levin2011-09-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently the method of dealing with an IO operation on a bus (PIO/MMIO) is to call the read or write callback for each device registered on the bus until we find a device which handles it. Since the number of devices on a bus can be significant due to ioeventfds and coalesced MMIO zones, this leads to a lot of overhead on each IO operation. Instead of registering devices, we now register ranges which points to a device. Lookup is done using an efficient bsearch instead of a linear search. Performance test was conducted by comparing exit count per second with 200 ioeventfds created on one byte and the guest is trying to access a different byte continuously (triggering usermode exits). Before the patch the guest has achieved 259k exits per second, after the patch the guest does 274k exits per second. Cc: Avi Kivity <avi@redhat.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Sasha Levin <levinsasha928@gmail.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* | | KVM: Use __print_symbolic() for vmexit tracepointsStefan Hajnoczi2011-09-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The vmexit tracepoints format the exit_reason to make it human-readable. Since the exit_reason depends on the instruction set (vmx or svm), formatting is handled with ftrace_print_symbols_seq() by referring to the appropriate exit reason table. However, the ftrace_print_symbols_seq() function is not meant to be used directly in tracepoints since it does not export the formatting table which userspace tools like trace-cmd and perf use to format traces. In practice perf dies when formatting vmexit-related events and trace-cmd falls back to printing the numeric value (with extra formatting code in the kvm plugin to paper over this limitation). Other userspace consumers of vmexit-related tracepoints would be in similar trouble. To avoid significant changes to the kvm_exit tracepoint, this patch moves the vmx and svm exit reason tables into arch/x86/kvm/trace.h and selects the right table with __print_symbolic() depending on the instruction set. Note that __print_symbolic() is designed for exporting the formatting table to userspace and allows trace-cmd and perf to work. Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* | | KVM: Record instruction set in all vmexit tracepointsStefan Hajnoczi2011-09-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The kvm_exit tracepoint recently added the isa argument to aid decoding exit_reason. The semantics of exit_reason depend on the instruction set (vmx or svm) and the isa argument allows traces to be analyzed on other machines. Add the isa argument to kvm_nested_vmexit and kvm_nested_vmexit_inject so these tracepoints can also be self-describing. Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* | | KVM: Really fix HV_X64_MSR_APIC_ASSIST_PAGEMike Waychison2011-09-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 0945d4b228 tried to fix the get_msr path for the HV_X64_MSR_APIC_ASSIST_PAGE msr, but was poorly tested. We should be returning 0 if the read succeeded, and passing the value back to the caller via the pdata out argument, not returning the value directly. Signed-off-by: Mike Waychison <mikew@google.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* | | KVM: x86: get_msr support for HV_X64_MSR_APIC_ASSIST_PAGEMike Waychison2011-09-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | "get" support for the HV_X64_MSR_APIC_ASSIST_PAGE msr was missing, even though it is explicitly enumerated as something the vmm should save in msrs_to_save and reported to userland via the KVM_GET_MSR_INDEX_LIST ioctl. Add "get" support for HV_X64_MSR_APIC_ASSIST_PAGE. We simply return the guest visible value of this register, which seems to be correct as a set on the register is validated for us already. Signed-off-by: Mike Waychison <mikew@google.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* | | KVM: x86: Raise the hard VCPU count limitSasha Levin2011-09-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The patch raises the hard limit of VCPU count to 254. This will allow developers to easily work on scalability and will allow users to test high VCPU setups easily without patching the kernel. To prevent possible issues with current setups, KVM_CAP_NR_VCPUS now returns the recommended VCPU limit (which is still 64) - this should be a safe value for everybody, while a new KVM_CAP_MAX_VCPUS returns the hard limit which is now 254. Cc: Avi Kivity <avi@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Pekka Enberg <penberg@kernel.org> Suggested-by: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Sasha Levin <levinsasha928@gmail.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* | | KVM: x86: cleanup the code of read/write emulationXiao Guangrong2011-09-25
| | | | | | | | | | | | | | | | | | | | | Using the read/write operation to remove the same code Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* | | KVM: x86: abstract the operation for read/write emulationXiao Guangrong2011-09-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | The operations of read emulation and write emulation are very similar, so we can abstract the operation of them, in larter patch, it is used to cleanup the same code Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* | | KVM: x86: fix broken read emulation spans a page boundaryXiao Guangrong2011-09-25
|/ / | | | | | | | | | | | | | | | | | | | | If the range spans a page boundary, the mmio access can be broke, fix it as write emulation. And we already get the guest physical address, so use it to read guest data directly to avoid walking guest page table again Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* | KVM: x86 emulator: fix Src2CL decodeAvi Kivity2011-09-25
| | | | | | | | | | | | | | | | | | | | Src2CL decode (used for double width shifts) erronously decodes only bit 3 of %rcx, instead of bits 7:0. Fix by decoding %cl in its entirety. Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* | KVM: MMU: fix incorrect return of spteZhao Jin2011-09-25
|/ | | | | | | | | | __update_clear_spte_slow should return original spte while the current code returns low half of original spte combined with high half of new spte. Signed-off-by: Zhao Jin <cronozhj@gmail.com> Reviewed-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* Merge branch 'kvm-updates/3.1' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds2011-08-16
|\ | | | | | | | | | | * 'kvm-updates/3.1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: uses TASKSTATS, depends on NET KVM: fix TASK_DELAY_ACCT kconfig warning
| * KVM: uses TASKSTATS, depends on NETRandy Dunlap2011-08-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | CONFIG_TASKSTATS just had a change to use netlink, including a change to "depends on NET". Since "select" does not follow dependencies, KVM also needs to depend on NET to prevent build errors when CONFIG_NET is not enabled. Sample of the reported "undefined reference" build errors: taskstats.c:(.text+0x8f686): undefined reference to `nla_put' taskstats.c:(.text+0x8f721): undefined reference to `nla_reserve' taskstats.c:(.text+0x8f8fb): undefined reference to `init_net' taskstats.c:(.text+0x8f905): undefined reference to `netlink_unicast' taskstats.c:(.text+0x8f934): undefined reference to `kfree_skb' taskstats.c:(.text+0x8f9e9): undefined reference to `skb_clone' taskstats.c:(.text+0x90060): undefined reference to `__alloc_skb' taskstats.c:(.text+0x901e9): undefined reference to `skb_put' taskstats.c:(.init.text+0x4665): undefined reference to `genl_register_family' taskstats.c:(.init.text+0x4699): undefined reference to `genl_register_ops' taskstats.c:(.init.text+0x4710): undefined reference to `genl_unregister_ops' taskstats.c:(.init.text+0x471c): undefined reference to `genl_unregister_family' Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
| * KVM: fix TASK_DELAY_ACCT kconfig warningRandy Dunlap2011-07-27
| | | | | | | | | | | | | | | | | | Fix kconfig dependency warning: warning: (KVM) selects TASK_DELAY_ACCT which has unmet direct dependencies (TASKSTATS) Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Avi Kivity <avi@redhat.com>
* | atomic: use <linux/atomic.h>Arun Sharma2011-07-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | This allows us to move duplicated code in <asm/atomic.h> (atomic_inc_not_zero() for now) to <linux/atomic.h> Signed-off-by: Arun Sharma <asharma@fb.com> Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: David Miller <davem@davemloft.net> Cc: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | Merge branch 'for-linus' of ↵Linus Torvalds2011-07-25
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (43 commits) fs: Merge split strings treewide: fix potentially dangerous trailing ';' in #defined values/expressions uwb: Fix misspelling of neighbourhood in comment net, netfilter: Remove redundant goto in ebt_ulog_packet trivial: don't touch files that are removed in the staging tree lib/vsprintf: replace link to Draft by final RFC number doc: Kconfig: `to be' -> `be' doc: Kconfig: Typo: square -> squared doc: Konfig: Documentation/power/{pm => apm-acpi}.txt drivers/net: static should be at beginning of declaration drivers/media: static should be at beginning of declaration drivers/i2c: static should be at beginning of declaration XTENSA: static should be at beginning of declaration SH: static should be at beginning of declaration MIPS: static should be at beginning of declaration ARM: static should be at beginning of declaration rcu: treewide: Do not use rcu_read_lock_held when calling rcu_dereference_check Update my e-mail address PCIe ASPM: forcedly -> forcibly gma500: push through device driver tree ... Fix up trivial conflicts: - arch/arm/mach-ep93xx/dma-m2p.c (deleted) - drivers/gpio/gpio-ep93xx.c (renamed and context nearby) - drivers/net/r8169.c (just context changes)
| * Merge branch 'master' into for-nextJiri Kosina2011-07-11
| |\ | | | | | | | | | | | | Sync with Linus' tree to be able to apply pending patches that are based on newer code already present upstream.
| * | treewide: remove duplicate includesVitaliy Ivanov2011-06-20
| | | | | | | | | | | | | | | | | | | | | | | | Many stupid corrections of duplicated includes based on the output of scripts/checkincludes.pl. Signed-off-by: Vitaliy Ivanov <vitalivanov@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* | | Merge branch 'kvm-updates/3.1' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds2011-07-24
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'kvm-updates/3.1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (143 commits) KVM: IOMMU: Disable device assignment without interrupt remapping KVM: MMU: trace mmio page fault KVM: MMU: mmio page fault support KVM: MMU: reorganize struct kvm_shadow_walk_iterator KVM: MMU: lockless walking shadow page table KVM: MMU: do not need atomicly to set/clear spte KVM: MMU: introduce the rules to modify shadow page table KVM: MMU: abstract some functions to handle fault pfn KVM: MMU: filter out the mmio pfn from the fault pfn KVM: MMU: remove bypass_guest_pf KVM: MMU: split kvm_mmu_free_page KVM: MMU: count used shadow pages on prepareing path KVM: MMU: rename 'pt_write' to 'emulate' KVM: MMU: cleanup for FNAME(fetch) KVM: MMU: optimize to handle dirty bit KVM: MMU: cache mmio info on page fault path KVM: x86: introduce vcpu_mmio_gva_to_gpa to cleanup the code KVM: MMU: do not update slot bitmap if spte is nonpresent KVM: MMU: fix walking shadow page table KVM guest: KVM Steal time registration ...
| * | | KVM: MMU: trace mmio page faultXiao Guangrong2011-07-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Add tracepoints to trace mmio page fault Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
| * | | KVM: MMU: mmio page fault supportXiao Guangrong2011-07-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The idea is from Avi: | We could cache the result of a miss in an spte by using a reserved bit, and | checking the page fault error code (or seeing if we get an ept violation or | ept misconfiguration), so if we get repeated mmio on a page, we don't need to | search the slot list/tree. | (https://lkml.org/lkml/2011/2/22/221) When the page fault is caused by mmio, we cache the info in the shadow page table, and also set the reserved bits in the shadow page table, so if the mmio is caused again, we can quickly identify it and emulate it directly Searching mmio gfn in memslots is heavy since we need to walk all memeslots, it can be reduced by this feature, and also avoid walking guest page table for soft mmu. [jan: fix operator precedence issue] Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Avi Kivity <avi@redhat.com>
| * | | KVM: MMU: reorganize struct kvm_shadow_walk_iteratorXiao Guangrong2011-07-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Reorganize it for good using the cache Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
| * | | KVM: MMU: lockless walking shadow page tableXiao Guangrong2011-07-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use rcu to protect shadow pages table to be freed, so we can safely walk it, it should run fastly and is needed by mmio page fault Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
| * | | KVM: MMU: do not need atomicly to set/clear spteXiao Guangrong2011-07-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now, the spte is just from nonprsent to present or present to nonprsent, so we can use some trick to set/clear spte non-atomicly as linux kernel does Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
| * | | KVM: MMU: introduce the rules to modify shadow page tableXiao Guangrong2011-07-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce some interfaces to modify spte as linux kernel does: - mmu_spte_clear_track_bits, it set the spte from present to nonpresent, and track the stat bits(accessed/dirty) of spte - mmu_spte_clear_no_track, the same as mmu_spte_clear_track_bits except tracking the stat bits - mmu_spte_set, set spte from nonpresent to present - mmu_spte_update, only update the stat bits Now, it does not allowed to set spte from present to present, later, we can drop the atomicly opration for X86_32 host, and it is the preparing work to get spte on X86_32 host out of the mmu lock Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
| * | | KVM: MMU: abstract some functions to handle fault pfnXiao Guangrong2011-07-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce handle_abnormal_pfn to handle fault pfn on page fault path, introduce mmu_invalid_pfn to handle fault pfn on prefetch path It is the preparing work for mmio page fault support Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
| * | | KVM: MMU: filter out the mmio pfn from the fault pfnXiao Guangrong2011-07-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If the page fault is caused by mmio, the gfn can not be found in memslots, and 'bad_pfn' is returned on gfn_to_hva path, so we can use 'bad_pfn' to identify the mmio page fault. And, to clarify the meaning of mmio pfn, we return fault page instead of bad page when the gfn is not allowd to prefetch Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
| * | | KVM: MMU: remove bypass_guest_pfXiao Guangrong2011-07-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The idea is from Avi: | Maybe it's time to kill off bypass_guest_pf=1. It's not as effective as | it used to be, since unsync pages always use shadow_trap_nonpresent_pte, | and since we convert between the two nonpresent_ptes during sync and unsync. Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
| * | | KVM: MMU: split kvm_mmu_free_pageXiao Guangrong2011-07-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Split kvm_mmu_free_page to kvm_mmu_isolate_page and kvm_mmu_free_page One is used to remove the page from cache under mmu lock and the other is used to free page table out of mmu lock Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
| * | | KVM: MMU: count used shadow pages on prepareing pathXiao Guangrong2011-07-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move counting used shadow pages from commiting path to preparing path to reduce tlb flush on some paths Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
| * | | KVM: MMU: rename 'pt_write' to 'emulate'Xiao Guangrong2011-07-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If 'pt_write' is true, we need to emulate the fault. And in later patch, we need to emulate the fault even though it is not a pt_write event, so rename it to better fit the meaning Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
| * | | KVM: MMU: cleanup for FNAME(fetch)Xiao Guangrong2011-07-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | gw->pte_access is the final access permission, since it is unified with gw->pt_access when we walked guest page table: FNAME(walk_addr_generic): pte_access = pt_access & FNAME(gpte_access)(vcpu, pte, true); Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
| * | | KVM: MMU: optimize to handle dirty bitXiao Guangrong2011-07-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If dirty bit is not set, we can make the pte access read-only to avoid handing dirty bit everywhere Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
| * | | KVM: MMU: cache mmio info on page fault pathXiao Guangrong2011-07-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If the page fault is caused by mmio, we can cache the mmio info, later, we do not need to walk guest page table and quickly know it is a mmio fault while we emulate the mmio instruction Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
generated by cgit v1.2.2 (git 2.25.0) at 2025-08-07 19:58:40 -0400