- 16 Oct, 2018 8 commits
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Andrew Jones authored
Signed-off-by:
Andrew Jones <drjones@redhat.com> Signed-off-by:
Paolo Bonzini <pbonzini@redhat.com>
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Andrew Jones authored
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Andrew Jones authored
Tidy up kvm-util code: code/comment formatting, remove unused code, and move x86 specific code out. We also move vcpu_dump() out of common code, because not all arches (AArch64) have KVM_GET_REGS. Signed-off-by:
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Andrew Jones authored
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Andrew Jones authored
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Andrew Jones authored
Rework the guest exit to userspace code to generalize the concept into what it is, a "hypercall to userspace", and provide two implementations of it: the PortIO version currently used, but only useable by x86, and an MMIO version that other architectures (except s390) can use. Signed-off-by:
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Andrew Jones authored
Guest code may want to call functions that have variable arguments. To do so, we either need to compile with -mno-sse or enable SSE in the VCPUs. As it should be pretty safe to turn on the feature, and -mno-sse would make linking test code with standard libraries difficult, we choose the feature enabling. Signed-off-by:
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Wanpeng Li authored
In cloud environment, lapic_timer_advance_ns is needed to be tuned for every CPU generations, and every host kernel versions(the kvm-unit-tests/tscdeadline_latency.flat is 5700 cycles for upstream kernel and 9600 cycles for our 3.10 product kernel, both preemption_timer=N, Skylake server). This patch adds the capability to automatically tune lapic_timer_advance_ns step by step, the initial value is 1000ns as 'commit d0659d94 ("KVM: x86: add option to advance tscdeadline hrtimer expiration")' recommended, it will be reduced when it is too early, and increased when it is too late. The guest_tsc and tsc_deadline are hard to equal, so we assume we are done when the delta is within a small scope e.g. 100 cycles. This patch reduces latency (kvm-unit-tests/tscdeadline_latency, busy waits, preemption_timer enabled) from ~2600 cyles to ~1200 cyles on our Skylake server. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Liran Alon <liran.alon@oracle.com> Signed-off-by:
Wanpeng Li <wanpengli@tencent.com> Signed-off-by:
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- 13 Oct, 2018 6 commits
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Liran Alon authored
If L1 uses VPID, it expects TLB to not be flushed on L1<->L2 transitions. However, code currently flushes TLB nonetheless if we didn't allocate a vpid02 for L2. As in this case, vmcs02->vpid == vmcs01->vpid == vmx->vpid. But, if L1 uses EPT, TLB entires populated by L2 are tagged with EPTP02 while TLB entries populated by L1 are tagged with EPTP01. Therefore, we can also avoid TLB flush if L1 uses VPID and EPT. Reviewed-by:
Mihai Carabas <mihai.carabas@oracle.com> Reviewed-by:
Darren Kenny <darren.kenny@oracle.com> Reviewed-by:
Nikita Leshenko <nikita.leshchenko@oracle.com> Signed-off-by:
Liran Alon <liran.alon@oracle.com> Signed-off-by:
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Liran Alon authored
All VPID12s used on a given L1 vCPU is translated to a single VPID02 (vmx->nested.vpid02 or vmx->vpid). Therefore, on L1->L2 VMEntry, we need to invalidate linear and combined mappings tagged by VPID02 in case L1 uses VPID and vmcs12->vpid was changed since last L1->L2 VMEntry. However, current code invalidates the wrong mappings as it calls __vmx_flush_tlb() with invalidate_gpa parameter set to true which will result in invalidating combined and guest-physical mappings tagged with active EPTP which is EPTP01. Similarly, INVVPID emulation have the exact same issue. Fix both issues by just setting invalidate_gpa parameter to false which will result in invalidating linear and combined mappings tagged with given VPID02 as required. Reviewed-by:
Mark Kanda <mark.kanda@oracle.com> Signed-off-by:
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Liran Alon authored
In case L0 didn't allocate vmx->nested.vpid02 for L2, vmcs02->vpid is set to vmx->vpid. Consider this case when emulating L1 INVVPID in L0. Reviewed-by:
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Liran Alon authored
If L1 and L2 share VPID (because L1 don't use VPID or we haven't allocated a vpid02), we need to flush TLB on L1<->L2 transitions. Before this patch, this TLB flushing was done by vmx_flush_tlb(). If L0 use EPT, this will translate into INVEPT(active_eptp); However, if L1 use EPT, in L1->L2 VMEntry, active EPTP is EPTP01 but TLB entries populated by L2 are tagged with EPTP02. Therefore we should delay vmx_flush_tlb() until active_eptp is EPTP02. To achieve this, instead of directly calling vmx_flush_tlb() we request it to be called by KVM_REQ_TLB_FLUSH which is evaluated after KVM_REQ_LOAD_CR3 which sets the active_eptp to EPTP02 as required. Similarly, on L2->L1 VMExit, active EPTP is EPTP02 but TLB entries populated by L1 are tagged with EPTP01 and therefore we should delay vmx_flush_tlb() until active_eptp is EPTP01. Reviewed-by:
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Sean Christopherson authored
The KVM_GUEST_CR0_MASK macro tracks CR0 bits that are forced to zero by the VMX architecture, i.e. CR0.{NW,CD} must always be zero in the hardware CR0 post-VMXON. Rename the macro to clarify its purpose, be consistent with KVM_VM_CR0_ALWAYS_ON and avoid confusion with the CR0_GUEST_HOST_MASK field. Signed-off-by:Sean Christopherson <sean.j.christopherson@intel.com> Reviewed-by:
Jim Mattson <jmattson@google.com> Signed-off-by:
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Paolo Bonzini authored
Merge tag 'kvm-s390-next-4.20-2' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD KVM: s390/vfio-ap: Fixes and enhancements for vfio-ap - add tracing - fix a locking bug - make local functions and data static
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- 10 Oct, 2018 1 commit
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Paolo Bonzini authored
Merge tag 'kvm-ppc-next-4.20-1' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc into HEAD PPC KVM update for 4.20. The major new feature here is nested HV KVM support. This allows the HV KVM module to load inside a radix guest on POWER9 and run radix guests underneath it. These nested guests can run in supervisor mode and don't require any additional instructions to be emulated, unlike with PR KVM, and so performance is much better than with PR KVM, and is very close to the performance of a non-nested guest. A nested hypervisor (a guest with nested guests) can be migrated to another host and will bring all its nested guests along with it. A nested guest can also itself run guests, and so on down to any desired depth of nesting. Apart from that there are a series of updates for IOMMU handling from Alexey Kardashevskiy, a "one VM per core" mode for HV KVM for security-paranoid applications, and a small fix for PR KVM.
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- 09 Oct, 2018 25 commits
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Paul Mackerras authored
This adds a KVM_PPC_NO_HASH flag to the flags field of the kvm_ppc_smmu_info struct, and arranges for it to be set when running as a nested hypervisor, as an unambiguous indication to userspace that HPT guests are not supported. Reporting the KVM_CAP_PPC_MMU_HASH_V3 capability as false could be taken as indicating only that the new HPT features in ISA V3.0 are not supported, leaving it ambiguous whether pre-V3.0 HPT features are supported. Reviewed-by:
David Gibson <david@gibson.dropbear.id.au> Signed-off-by:
Paul Mackerras <paulus@ozlabs.org>
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Paul Mackerras authored
With this, userspace can enable a KVM-HV guest to run nested guests under it. The administrator can control whether any nested guests can be run; setting the "nested" module parameter to false prevents any guests becoming nested hypervisors (that is, any attempt to enable the nested capability on a guest will fail). Guests which are already nested hypervisors will continue to be so. Reviewed-by:
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Paul Mackerras authored
This merges in the "ppc-kvm" topic branch of the powerpc tree to get a series of commits that touch both general arch/powerpc code and KVM code. These commits will be merged both via the KVM tree and the powerpc tree. Signed-off-by: -
Paul Mackerras authored
This adds a list of valid shadow PTEs for each nested guest to the 'radix' file for the guest in debugfs. This can be useful for debugging. Reviewed-by:
Michael Ellerman <mpe@ellerman.id.au>
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Paul Mackerras authored
With this, the KVM-HV module can be loaded in a guest running under KVM-HV, and if the hypervisor supports nested virtualization, this guest can now act as a nested hypervisor and run nested guests. This also adds some checks to inform userspace that HPT guests are not supported by nested hypervisors (by returning false for the KVM_CAP_PPC_MMU_HASH_V3 capability), and to prevent userspace from configuring a guest to use HPT mode. Signed-off-by:
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Suraj Jitindar Singh authored
The hcall H_ENTER_NESTED takes two parameters: the address in L1 guest memory of a hv_regs struct and the address of a pt_regs struct. The hcall requests the L0 hypervisor to use the register values in these structs to run a L2 guest and to return the exit state of the L2 guest in these structs. These are in the endianness of the L1 guest, rather than being always big-endian as is usually the case for PAPR hypercalls. This is convenient because it means that the L1 guest can pass the address of the regs field in its kvm_vcpu_arch struct. This also improves performance slightly by avoiding the need for two copies of the pt_regs struct. When reading/writing these structures, this patch handles the case where the endianness of the L1 guest differs from that of the L0 hypervisor, by byteswapping the structures after reading and before writing them back. Since all the fields of the pt_regs are of the same type, i.e., unsigned long, we treat it as an array of unsigned longs. The fields of struct hv_guest_state are not all the same, so its fields are byteswapped individually. Reviewed-by:
Suraj Jitindar Singh <sjitindarsingh@gmail.com> Signed-off-by:
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Suraj Jitindar Singh authored
restore_hv_regs() is used to copy the hv_regs L1 wants to set to run the nested (L2) guest into the vcpu structure. We need to sanitise these values to ensure we don't let the L1 guest hypervisor do things we don't want it to. We don't let data address watchpoints or completed instruction address breakpoints be set to match in hypervisor state. We also don't let L1 enable features in the hypervisor facility status and control register (HFSCR) for L2 which we have disabled for L1. That is L2 will get the subset of features which the L0 hypervisor has enabled for L1 and the features L1 wants to enable for L2. This could mean we give L1 a hypervisor facility unavailable interrupt for a facility it thinks it has enabled, however it shouldn't have enabled a facility it itself doesn't have for the L2 guest. We sanitise the registers when copying in the L2 hv_regs. We don't need to sanitise when copying back the L1 hv_regs since these shouldn't be able to contain invalid values as they're just what was copied out. Reviewed-by:
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Paul Mackerras authored
This adds a one-reg register identifier which can be used to read and set the virtual PTCR for the guest. This register identifies the address and size of the virtual partition table for the guest, which contains information about the nested guests under this guest. Migrating this value is the only extra requirement for migrating a guest which has nested guests (assuming of course that the destination host supports nested virtualization in the kvm-hv module). Reviewed-by:
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Paul Mackerras authored
When running as a nested hypervisor, this avoids reading hypervisor privileged registers (specifically HFSCR, LPIDR and LPCR) at startup; instead reasonable default values are used. This also avoids writing LPIDR in the single-vcpu entry/exit path. Also, this removes the check for CPU_FTR_HVMODE in kvmppc_mmu_hv_init() since its only caller already checks this. Reviewed-by:
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Suraj Jitindar Singh authored
This is only done at level 0, since only level 0 knows which physical CPU a vcpu is running on. This does for nested guests what L0 already did for its own guests, which is to flush the TLB on a pCPU when it goes to run a vCPU there, and there is another vCPU in the same VM which previously ran on this pCPU and has now started to run on another pCPU. This is to handle the situation where the other vCPU touched a mapping, moved to another pCPU and did a tlbiel (local-only tlbie) on that new pCPU and thus left behind a stale TLB entry on this pCPU. This introduces a limit on the the vcpu_token values used in the H_ENTER_NESTED hcall -- they must now be less than NR_CPUS. [paulus@ozlabs.org - made prev_cpu array be short[] to reduce memory consumption.] Reviewed-by:
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Paul Mackerras authored
This adds code to call the H_TLB_INVALIDATE hypercall when running as a guest, in the cases where we need to invalidate TLBs (or other MMU caches) as part of managing the mappings for a nested guest. Calling H_TLB_INVALIDATE lets the nested hypervisor inform the parent hypervisor about changes to partition-scoped page tables or the partition table without needing to do hypervisor-privileged tlbie instructions. Reviewed-by:
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Suraj Jitindar Singh authored
When running a nested (L2) guest the guest (L1) hypervisor will use the H_TLB_INVALIDATE hcall when it needs to change the partition scoped page tables or the partition table which it manages. It will use this hcall in the situations where it would use a partition-scoped tlbie instruction if it were running in hypervisor mode. The H_TLB_INVALIDATE hcall can invalidate different scopes: Invalidate TLB for a given target address: - This invalidates a single L2 -> L1 pte - We need to invalidate any L2 -> L0 shadow_pgtable ptes which map the L2 address space which is being invalidated. This is because a single L2 -> L1 pte may have been mapped with more than one pte in the L2 -> L0 page tables. Invalidate the entire TLB for a given LPID or for all LPIDs: - Invalidate the entire shadow_pgtable for a given nested guest, or for all nested guests. Invalidate the PWC (page walk cache) for a given LPID or for all LPIDs: - We don't cache the PWC, so nothing to do. Invalidate the entire TLB, PWC and partition table for a given/all LPIDs: - Here we re-read the partition table entry and remove the nested state for any nested guest for which the first doubleword of the partition table entry is now zero. The H_TLB_INVALIDATE hcall takes as parameters the tlbie instruction word (of which only the RIC, PRS and R fields are used), the rS value (giving the lpid, where required) and the rB value (giving the IS, AP and EPN values). [paulus@ozlabs.org - adapted to having the partition table in guest memory, added the H_TLB_INVALIDATE implementation, removed tlbie instruction emulation, reworded the commit message.] Reviewed-by:
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Suraj Jitindar Singh authored
When a host (L0) page which is mapped into a (L1) guest is in turn mapped through to a nested (L2) guest we keep a reverse mapping (rmap) so that these mappings can be retrieved later. Whenever we create an entry in a shadow_pgtable for a nested guest we create a corresponding rmap entry and add it to the list for the L1 guest memslot at the index of the L1 guest page it maps. This means at the L1 guest memslot we end up with lists of rmaps. When we are notified of a host page being invalidated which has been mapped through to a (L1) guest, we can then walk the rmap list for that guest page, and find and invalidate all of the corresponding shadow_pgtable entries. In order to reduce memory consumption, we compress the information for each rmap entry down to 52 bits -- 12 bits for the LPID and 40 bits for the guest real page frame number -- which will fit in a single unsigned long. To avoid a scenario where a guest can trigger unbounded memory allocations, we scan the list when adding an entry to see if there is already an entry with the contents we need. This can occur, because we don't ever remove entries from the middle of a list. A struct nested guest rmap is a list pointer and an rmap entry; ---------------- | next pointer | ---------------- | rmap entry | ---------------- Thus the rmap pointer for each guest frame number in the memslot can be either NULL, a single entry, or a pointer to a list of nested rmap entries. gfn memslot rmap array ------------------------- 0 | NULL | (no rmap entry) ------------------------- 1 | single rmap entry | (rmap entry with low bit set) ------------------------- 2 | list head pointer | (list of rmap entries) ------------------------- The final entry always has the lowest bit set and is stored in the next pointer of the last list entry, or as a single rmap entry. With a list of rmap entries looking like; ----------------- ----------------- ------------------------- | list head ptr | ----> | next pointer | ----> | single rmap entry | ----------------- ----------------- ------------------------- | rmap entry | | rmap entry | ----------------- ------------------------- Signed-off-by:
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Suraj Jitindar Singh authored
Consider a normal (L1) guest running under the main hypervisor (L0), and then a nested guest (L2) running under the L1 guest which is acting as a nested hypervisor. L0 has page tables to map the address space for L1 providing the translation from L1 real address -> L0 real address; L1 | | (L1 -> L0) | ----> L0 There are also page tables in L1 used to map the address space for L2 providing the translation from L2 real address -> L1 read address. Since the hardware can only walk a single level of page table, we need to maintain in L0 a "shadow_pgtable" for L2 which provides the translation from L2 real address -> L0 real address. Which looks like; L2 L2 | | | (L2 -> L1) | | | ----> L1 | (L2 -> L0) | | | (L1 -> L0) | | | ----> L0 --------> L0 When a page fault occurs while running a nested (L2) guest we need to insert a pte into this "shadow_pgtable" for the L2 -> L0 mapping. To do this we need to: 1. Walk the pgtable in L1 memory to find the L2 -> L1 mapping, and provide a page fault to L1 if this mapping doesn't exist. 2. Use our L1 -> L0 pgtable to convert this L1 address to an L0 address, or try to insert a pte for that mapping if it doesn't exist. 3. Now we have a L2 -> L0 mapping, insert this into our shadow_pgtable Once this mapping exists we can take rc faults when hardware is unable to automatically set the reference and change bits in the pte. On these we need to: 1. Check the rc bits on the L2 -> L1 pte match, and otherwise reflect the fault down to L1. 2. Set the rc bits in the L1 -> L0 pte which corresponds to the same host page. 3. Set the rc bits in the L2 -> L0 pte. As we reuse a large number of functions in book3s_64_mmu_radix.c for this we also needed to refactor a number of these functions to take an lpid parameter so that the correct lpid is used for tlb invalidations. The functionality however has remained the same. Reviewed-by:
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Paul Mackerras authored
When we are running as a nested hypervisor, we use a hypercall to enter the guest rather than code in book3s_hv_rmhandlers.S. This means that the hypercall handlers listed in hcall_real_table never get called. There are some hypercalls that are handled there and not in kvmppc_pseries_do_hcall(), which therefore won't get processed for a nested guest. To fix this, we add cases to kvmppc_pseries_do_hcall() to handle those hypercalls, with the following exceptions: - The HPT hypercalls (H_ENTER, H_REMOVE, etc.) are not handled because we only support radix mode for nested guests. - H_CEDE has to be handled specially because the cede logic in kvmhv_run_single_vcpu assumes that it has been processed by the time that kvmhv_p9_guest_entry() returns. Therefore we put a special case for H_CEDE in kvmhv_p9_guest_entry(). For the XICS hypercalls, if real-mode processing is enabled, then the virtual-mode handlers assume that they are being called only to finish up the operation. Therefore we turn off the real-mode flag in the XICS code when running as a nested hypervisor. Reviewed-by:
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Paul Mackerras authored
This adds code to call the H_IPI and H_EOI hypercalls when we are running as a nested hypervisor (i.e. without the CPU_FTR_HVMODE cpu feature) and we would otherwise access the XICS interrupt controller directly or via an OPAL call. Reviewed-by:
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Paul Mackerras authored
This adds a new hypercall, H_ENTER_NESTED, which is used by a nested hypervisor to enter one of its nested guests. The hypercall supplies register values in two structs. Those values are copied by the level 0 (L0) hypervisor (the one which is running in hypervisor mode) into the vcpu struct of the L1 guest, and then the guest is run until an interrupt or error occurs which needs to be reported to L1 via the hypercall return value. Currently this assumes that the L0 and L1 hypervisors are the same endianness, and the structs passed as arguments are in native endianness. If they are of different endianness, the version number check will fail and the hcall will be rejected. Nested hypervisors do not support indep_threads_mode=N, so this adds code to print a warning message if the administrator has set indep_threads_mode=N, and treat it as Y. Reviewed-by:
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Paul Mackerras authored
This starts the process of adding the code to support nested HV-style virtualization. It defines a new H_SET_PARTITION_TABLE hypercall which a nested hypervisor can use to set the base address and size of a partition table in its memory (analogous to the PTCR register). On the host (level 0 hypervisor) side, the H_SET_PARTITION_TABLE hypercall from the guest is handled by code that saves the virtual PTCR value for the guest. This also adds code for creating and destroying nested guests and for reading the partition table entry for a nested guest from L1 memory. Each nested guest has its own shadow LPID value, different in general from the LPID value used by the nested hypervisor to refer to it. The shadow LPID value is allocated at nested guest creation time. Nested hypervisor functionality is only available for a radix guest, which therefore means a radix host on a POWER9 (or later) processor. Signed-off-by:
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Paul Mackerras authored
kvmppc_unmap_pte() does a sequence of operations that are open-coded in kvm_unmap_radix(). This extends kvmppc_unmap_pte() a little so that it can be used by kvm_unmap_radix(), and makes kvm_unmap_radix() call it. Reviewed-by:
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Suraj Jitindar Singh authored
The radix page fault handler accounts for all cases, including just needing to insert a pte. This breaks it up into separate functions for the two main cases; setting rc and inserting a pte. This allows us to make the setting of rc and inserting of a pte generic for any pgtable, not specific to the one for this guest. [paulus@ozlabs.org - reduced diffs from previous code] Reviewed-by:
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Suraj Jitindar Singh authored
kvmppc_mmu_radix_xlate() is used to translate an effective address through the process tables. The process table and partition tables have identical layout. Exploit this fact to make the kvmppc_mmu_radix_xlate() function able to translate either an effective address through the process tables or a guest real address through the partition tables. [paulus@ozlabs.org - reduced diffs from previous code] Reviewed-by:
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Suraj Jitindar Singh authored
When destroying a VM we return the LPID to the pool, however we never zero the partition table entry. This is instead done when we reallocate the LPID. Zero the partition table entry on VM teardown before returning the LPID to the pool. This means if we were running as a nested hypervisor the real hypervisor could use this to determine when it can free resources. Reviewed-by:
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Paul Mackerras authored
When the 'regs' field was added to struct kvm_vcpu_arch, the code was changed to use several of the fields inside regs (e.g., gpr, lr, etc.) but not the ccr field, because the ccr field in struct pt_regs is 64 bits on 64-bit platforms, but the cr field in kvm_vcpu_arch is only 32 bits. This changes the code to use the regs.ccr field instead of cr, and changes the assembly code on 64-bit platforms to use 64-bit loads and stores instead of 32-bit ones. Reviewed-by:
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Paul Mackerras authored
This adds a file called 'radix' in the debugfs directory for the guest, which when read gives all of the valid leaf PTEs in the partition-scoped radix tree for a radix guest, in human-readable format. It is analogous to the existing 'htab' file which dumps the HPT entries for a HPT guest. Reviewed-by:
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Paul Mackerras authored
Currently the code for handling hypervisor instruction page faults passes 0 for the flags indicating the type of fault, which is OK in the usual case that the page is not mapped in the partition-scoped page tables. However, there are other causes for hypervisor instruction page faults, such as not being to update a reference (R) or change (C) bit. The cause is indicated in bits in HSRR1, including a bit which indicates that the fault is due to not being able to write to a page (for example to update an R or C bit). Not handling these other kinds of faults correctly can lead to a loop of continual faults without forward progress in the guest. In order to handle these faults better, this patch constructs a "DSISR-like" value from the bits which DSISR and SRR1 (for a HISI) have in common, and passes it to kvmppc_book3s_hv_page_fault() so that it knows what caused the fault. Reviewed-by:
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