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2021-02-18KVM: nSVM: move nested vmrun tracepoint to enter_svm_guest_modeMaxim Levitsky
This way trace will capture all the nested mode entries (including entries after migration, and from smm) Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20210217145718.1217358-3-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-02-04KVM: x86: SEV: Treat C-bit as legal GPA bit regardless of vCPU modeSean Christopherson
Rename cr3_lm_rsvd_bits to reserved_gpa_bits, and use it for all GPA legality checks. AMD's APM states: If the C-bit is an address bit, this bit is masked from the guest physical address when it is translated through the nested page tables. Thus, any access that can conceivably be run through NPT should ignore the C-bit when checking for validity. For features that KVM emulates in software, e.g. MTRRs, there is no clear direction in the APM for how the C-bit should be handled. For such cases, follow the SME behavior inasmuch as possible, since SEV is is essentially a VM-specific variant of SME. For SME, the APM states: In this case the upper physical address bits are treated as reserved when the feature is enabled except where otherwise indicated. Collecting the various relavant SME snippets in the APM and cross- referencing the omissions with Linux kernel code, this leaves MTTRs and APIC_BASE as the only flows that KVM emulates that should _not_ ignore the C-bit. Note, this means the reserved bit checks in the page tables are technically broken. This will be remedied in a future patch. Although the page table checks are technically broken, in practice, it's all but guaranteed to be irrelevant. NPT is required for SEV, i.e. shadowing page tables isn't needed in the common case. Theoretically, the checks could be in play for nested NPT, but it's extremely unlikely that anyone is running nested VMs on SEV, as doing so would require L1 to expose sensitive data to L0, e.g. the entire VMCB. And if anyone is running nested VMs, L0 can't read the guest's encrypted memory, i.e. L1 would need to put its NPT in shared memory, in which case the C-bit will never be set. Or, L1 could use shadow paging, but again, if L0 needs to read page tables, e.g. to load PDPTRs, the memory can't be encrypted if L1 has any expectation of L0 doing the right thing. Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20210204000117.3303214-8-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-02-04KVM: nSVM: Use common GPA helper to check for illegal CR3Sean Christopherson
Replace an open coded check for an invalid CR3 with its equivalent helper. No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20210204000117.3303214-7-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-02-04KVM: nSVM: Don't strip host's C-bit from guest's CR3 when reading PDPTRsSean Christopherson
Don't clear the SME C-bit when reading a guest PDPTR, as the GPA (CR3) is in the guest domain. Barring a bizarre paravirtual use case, this is likely a benign bug. SME is not emulated by KVM, loading SEV guest PDPTRs is doomed as KVM can't use the correct key to read guest memory, and setting guest MAXPHYADDR higher than the host, i.e. overlapping the C-bit, would cause faults in the guest. Note, for SEV guests, stripping the C-bit is technically aligned with CPU behavior, but for KVM it's the greater of two evils. Because KVM doesn't have access to the guest's encryption key, ignoring the C-bit would at best result in KVM reading garbage. By keeping the C-bit, KVM will fail its read (unless userspace creates a memslot with the C-bit set). The guest will still undoubtedly die, as KVM will use '0' for the PDPTR value, but that's preferable to interpreting encrypted data as a PDPTR. Fixes: d0ec49d4de90 ("kvm/x86/svm: Support Secure Memory Encryption within KVM") Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20210204000117.3303214-3-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-02-04KVM: X86: Rename DR6_INIT to DR6_ACTIVE_LOWChenyi Qiang
DR6_INIT contains the 1-reserved bits as well as the bit that is cleared to 0 when the condition (e.g. RTM) happens. The value can be used to initialize dr6 and also be the XOR mask between the #DB exit qualification (or payload) and DR6. Concerning that DR6_INIT is used as initial value only once, rename it to DR6_ACTIVE_LOW and apply it in other places, which would make the incoming changes for bus lock debug exception more simple. Signed-off-by: Chenyi Qiang <chenyi.qiang@intel.com> Message-Id: <20210202090433.13441-2-chenyi.qiang@intel.com> [Define DR6_FIXED_1 from DR6_ACTIVE_LOW and DR6_VOLATILE. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-02-03KVM: x86: cleanup CR3 reserved bits checksPaolo Bonzini
If not in long mode, the low bits of CR3 are reserved but not enforced to be zero, so remove those checks. If in long mode, however, the MBZ bits extend down to the highest physical address bit of the guest, excluding the encryption bit. Make the checks consistent with the above, and match them between nested_vmcb_checks and KVM_SET_SREGS. Cc: stable@vger.kernel.org Fixes: 761e41693465 ("KVM: nSVM: Check that MBZ bits in CR3 and CR4 are not set on vmrun of nested guests") Fixes: a780a3ea6282 ("KVM: X86: Fix reserved bits check for MOV to CR3") Reviewed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-01-25KVM: x86: allow KVM_REQ_GET_NESTED_STATE_PAGES outside guest mode for VMXPaolo Bonzini
VMX also uses KVM_REQ_GET_NESTED_STATE_PAGES for the Hyper-V eVMCS, which may need to be loaded outside guest mode. Therefore we cannot WARN in that case. However, that part of nested_get_vmcs12_pages is _not_ needed at vmentry time. Split it out of KVM_REQ_GET_NESTED_STATE_PAGES handling, so that both vmentry and migration (and in the latter case, independent of is_guest_mode) do the parts that are needed. Cc: <stable@vger.kernel.org> # 5.10.x: f2c7ef3ba: KVM: nSVM: cancel KVM_REQ_GET_NESTED_STATE_PAGES Cc: <stable@vger.kernel.org> # 5.10.x Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-01-07KVM: nSVM: cancel KVM_REQ_GET_NESTED_STATE_PAGES on nested vmexitMaxim Levitsky
It is possible to exit the nested guest mode, entered by svm_set_nested_state prior to first vm entry to it (e.g due to pending event) if the nested run was not pending during the migration. In this case we must not switch to the nested msr permission bitmap. Also add a warning to catch similar cases in the future. Fixes: a7d5c7ce41ac1 ("KVM: nSVM: delay MSR permission processing to first nested VM run") Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20210107093854.882483-2-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-01-07KVM: nSVM: mark vmcb as dirty when forcingly leaving the guest modeMaxim Levitsky
We overwrite most of vmcb fields while doing so, so we must mark it as dirty. Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20210107093854.882483-5-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-01-07KVM: nSVM: correctly restore nested_run_pending on migrationMaxim Levitsky
The code to store it on the migration exists, but no code was restoring it. One of the side effects of fixing this is that L1->L2 injected events are no longer lost when migration happens with nested run pending. Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20210107093854.882483-3-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-11-27KVM: nSVM: set fixed bits by handPaolo Bonzini
SVM generally ignores fixed-1 bits. Set them manually so that we do not end up by mistake without those bits set in struct kvm_vcpu; it is part of userspace API that KVM always returns value with the bits set. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-11-15KVM: x86: Return bool instead of int for CR4 and SREGS validity checksSean Christopherson
Rework the common CR4 and SREGS checks to return a bool instead of an int, i.e. true/false instead of 0/-EINVAL, and add "is" to the name to clarify the polarity of the return value (which is effectively inverted by this change). No functional changed intended. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Message-Id: <20201007014417.29276-6-sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-21KVM: nSVM: implement on demand allocation of the nested stateMaxim Levitsky
This way we don't waste memory on VMs which don't use nesting virtualization even when the host enabled it for them. Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20201001112954.6258-5-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-09-28KVM: nSVM: delay MSR permission processing to first nested VM runPaolo Bonzini
Allow userspace to set up the memory map after KVM_SET_NESTED_STATE; to do so, move the call to nested_svm_vmrun_msrpm inside the KVM_REQ_GET_NESTED_STATE_PAGES handler (which is currently not used by nSVM). This is similar to what VMX does already. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-09-28KVM: nSVM: CR3 MBZ bits are only 63:52Krish Sadhukhan
Commit 761e4169346553c180bbd4a383aedd72f905bc9a created a wrong mask for the CR3 MBZ bits. According to APM vol 2, only the upper 12 bits are MBZ. Fixes: 761e41693465 ("KVM: nSVM: Check that MBZ bits in CR3 and CR4 are not set on vmrun of nested guests", 2020-07-08) Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> Message-Id: <20200829004824.4577-2-krish.sadhukhan@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-09-28KVM: SVM: Add new intercept word in vmcb_control_areaBabu Moger
The new intercept bits have been added in vmcb control area to support few more interceptions. Here are the some of them. - INTERCEPT_INVLPGB, - INTERCEPT_INVLPGB_ILLEGAL, - INTERCEPT_INVPCID, - INTERCEPT_MCOMMIT, - INTERCEPT_TLBSYNC, Add a new intercept word in vmcb_control_area to support these instructions. Also update kvm_nested_vmrun trace function to support the new addition. AMD documentation for these instructions is available at "AMD64 Architecture Programmer’s Manual Volume 2: System Programming, Pub. 24593 Rev. 3.34(or later)" The documentation can be obtained at the links below: Link: https://www.amd.com/system/files/TechDocs/24593.pdf Link: https://bugzilla.kernel.org/show_bug.cgi?id=206537 Signed-off-by: Babu Moger <babu.moger@amd.com> Reviewed-by: Jim Mattson <jmattson@google.com> Message-Id: <159985251547.11252.16994139329949066945.stgit@bmoger-ubuntu> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-09-28KVM: SVM: Modify 64 bit intercept field to two 32 bit vectorsBabu Moger
Convert all the intercepts to one array of 32 bit vectors in vmcb_control_area. This makes it easy for future intercept vector additions. Also update trace functions. Signed-off-by: Babu Moger <babu.moger@amd.com> Reviewed-by: Jim Mattson <jmattson@google.com> Message-Id: <159985250813.11252.5736581193881040525.stgit@bmoger-ubuntu> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-09-28KVM: SVM: Modify intercept_exceptions to generic interceptsBabu Moger
Modify intercept_exceptions to generic intercepts in vmcb_control_area. Use the generic vmcb_set_intercept, vmcb_clr_intercept and vmcb_is_intercept to set/clear/test the intercept_exceptions bits. Signed-off-by: Babu Moger <babu.moger@amd.com> Reviewed-by: Jim Mattson <jmattson@google.com> Message-Id: <159985250037.11252.1361972528657052410.stgit@bmoger-ubuntu> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-09-28KVM: SVM: Change intercept_dr to generic interceptsBabu Moger
Modify intercept_dr to generic intercepts in vmcb_control_area. Use the generic vmcb_set_intercept, vmcb_clr_intercept and vmcb_is_intercept to set/clear/test the intercept_dr bits. Signed-off-by: Babu Moger <babu.moger@amd.com> Reviewed-by: Jim Mattson <jmattson@google.com> Message-Id: <159985249255.11252.10000868032136333355.stgit@bmoger-ubuntu> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-09-28KVM: SVM: Change intercept_cr to generic interceptsBabu Moger
Change intercept_cr to generic intercepts in vmcb_control_area. Use the new vmcb_set_intercept, vmcb_clr_intercept and vmcb_is_intercept where applicable. Signed-off-by: Babu Moger <babu.moger@amd.com> Reviewed-by: Jim Mattson <jmattson@google.com> Message-Id: <159985248506.11252.9081085950784508671.stgit@bmoger-ubuntu> [Change constant names. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-09-28KVM: SVM: Introduce vmcb_(set_intercept/clr_intercept/_is_intercept)Babu Moger
This is in preparation for the future intercept vector additions. Add new functions vmcb_set_intercept, vmcb_clr_intercept and vmcb_is_intercept using kernel APIs __set_bit, __clear_bit and test_bit espectively. Signed-off-by: Babu Moger <babu.moger@amd.com> Reviewed-by: Jim Mattson <jmattson@google.com> Message-Id: <159985247876.11252.16039238014239824460.stgit@bmoger-ubuntu> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-09-28KVM: nSVM: Remove unused fieldBabu Moger
host_intercept_exceptions is not used anywhere. Clean it up. Signed-off-by: Babu Moger <babu.moger@amd.com> Reviewed-by: Jim Mattson <jmattson@google.com> Message-Id: <159985252277.11252.8819848322175521354.stgit@bmoger-ubuntu> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-09-28KVM: nSVM: rename nested vmcb to vmcb12Maxim Levitsky
This is to be more consistient with VMX, and to support upcoming addition of vmcb02 Hopefully no functional changes. Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20200827171145.374620-3-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-09-28KVM: nSVM: Avoid freeing uninitialized pointers in svm_set_nested_state()Vitaly Kuznetsov
The save and ctl pointers are passed uninitialized to kfree() when svm_set_nested_state() follows the 'goto out_set_gif' path. While the issue could've been fixed by initializing these on-stack varialbles to NULL, it seems preferable to eliminate 'out_set_gif' label completely as it is not actually a failure path and duplicating a single svm_set_gif() call doesn't look too bad. [ bp: Drop obscure Addresses-Coverity: tag. ] Fixes: 6ccbd29ade0d ("KVM: SVM: nested: Don't allocate VMCB structures on stack") Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Reported-by: Joerg Roedel <jroedel@suse.de> Reported-by: Colin King <colin.king@canonical.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com> Acked-by: Joerg Roedel <jroedel@suse.de> Tested-by: Tom Lendacky <thomas.lendacky@amd.com> Link: https://lkml.kernel.org/r/20200914133725.650221-1-vkuznets@redhat.com Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-09-22Merge branch 'x86-seves-for-paolo' of ↵Paolo Bonzini
https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into HEAD
2020-09-12SVM: nSVM: setup nested msr permission bitmap on nested state loadMaxim Levitsky
This code was missing and was forcing the L2 run with L1's msr permission bitmap Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20200827162720.278690-3-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-09-12SVM: nSVM: correctly restore GIF on vmexit from nesting after migrationMaxim Levitsky
Currently code in svm_set_nested_state copies the current vmcb control area to L1 control area (hsave->control), under assumption that it mostly reflects the defaults that kvm choose, and later qemu overrides these defaults with L2 state using standard KVM interfaces, like KVM_SET_REGS. However nested GIF (which is AMD specific thing) is by default is true, and it is copied to hsave area as such. This alone is not a big deal since on VMexit, GIF is always set to false, regardless of what it was on VM entry. However in nested_svm_vmexit we were first were setting GIF to false, but then we overwrite the control fields with value from the hsave area. (including the nested GIF field itself if GIF virtualization is enabled). Now on normal vm entry this is not a problem, since GIF is usually false prior to normal vm entry, and this is the value that copied to hsave, and then restored, but this is not always the case when the nested state is loaded as explained above. To fix this issue, move svm_set_gif after we restore the L1 control state in nested_svm_vmexit, so that even with wrong GIF in the saved L1 control area, we still clear GIF as the spec says. Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20200827162720.278690-2-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-09-07KVM: SVM: nested: Don't allocate VMCB structures on stackJoerg Roedel
Do not allocate a vmcb_control_area and a vmcb_save_area on the stack, as these structures will become larger with future extenstions of SVM and thus the svm_set_nested_state() function will become a too large stack frame. Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20200907131613.12703-2-joro@8bytes.org
2020-07-30KVM: nSVM: Correctly set the shadow NPT root level in its MMU roleSean Christopherson
Move the initialization of shadow NPT MMU's shadow_root_level into kvm_init_shadow_npt_mmu() and explicitly set the level in the shadow NPT MMU's role to be the TDP level. This ensures the role and MMU levels are synchronized and also initialized before __kvm_mmu_new_pgd(), which consumes the level when attempting a fast PGD switch. Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Fixes: 9fa72119b24db ("kvm: x86: Introduce kvm_mmu_calc_root_page_role()") Fixes: a506fdd223426 ("KVM: nSVM: implement nested_svm_load_cr3() and use it for host->guest switch") Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Message-Id: <20200716034122.5998-2-sean.j.christopherson@intel.com> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Tested-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-10KVM: nSVM: remove nonsensical EXITINFO1 adjustment on nested NPFPaolo Bonzini
The "if" that drops the present bit from the page structure fauls makes no sense. It was added by yours truly in order to be bug-compatible with pre-existing code and in order to make the tests pass; however, the tests are wrong. The behavior after this patch matches bare metal. Reported-by: Nadav Amit <namit@vmware.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-10KVM: nSVM: use nested_svm_load_cr3() on guest->host switchVitaly Kuznetsov
Make nSVM code resemble nVMX where nested_vmx_load_cr3() is used on both guest->host and host->guest transitions. Also, we can now eliminate unconditional kvm_mmu_reset_context() and speed things up. Note, nVMX has two different paths: load_vmcs12_host_state() and nested_vmx_restore_host_state() and the later is used to restore from 'partial' switch to L2, it always uses kvm_mmu_reset_context(). nSVM doesn't have this yet. Also, nested_svm_vmexit()'s return value is almost always ignored nowadays. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20200710141157.1640173-9-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-10KVM: nSVM: implement nested_svm_load_cr3() and use it for host->guest switchVitaly Kuznetsov
Undesired triple fault gets injected to L1 guest on SVM when L2 is launched with certain CR3 values. #TF is raised by mmu_check_root() check in fast_pgd_switch() and the root cause is that when kvm_set_cr3() is called from nested_prepare_vmcb_save() with NPT enabled CR3 points to a nGPA so we can't check it with kvm_is_visible_gfn(). Using generic kvm_set_cr3() when switching to nested guest is not a great idea as we'll have to distinguish between 'real' CR3s and 'nested' CR3s to e.g. not call kvm_mmu_new_pgd() with nGPA. Following nVMX implement nested-specific nested_svm_load_cr3() doing the job. To support the change, nested_svm_load_cr3() needs to be re-ordered with nested_svm_init_mmu_context(). Note: the current implementation is sub-optimal as we always do TLB flush/MMU sync but this is still an improvement as we at least stop doing kvm_mmu_reset_context(). Fixes: 7c390d350f8b ("kvm: x86: Add fast CR3 switch code path") Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20200710141157.1640173-8-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-10KVM: nSVM: move kvm_set_cr3() after nested_svm_uninit_mmu_context()Vitaly Kuznetsov
kvm_mmu_new_pgd() refers to arch.mmu and at this point it still references arch.guest_mmu while arch.root_mmu is expected. Note, the change is effectively a nop: when !npt_enabled, nested_svm_uninit_mmu_context() does nothing (as we don't do nested_svm_init_mmu_context()) and with npt_enabled we don't do kvm_set_cr3(). However, it will matter when we move the call to kvm_mmu_new_pgd into nested_svm_load_cr3(). No functional change intended. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20200710141157.1640173-7-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-10KVM: nSVM: introduce nested_svm_load_cr3()/nested_npt_enabled()Vitaly Kuznetsov
As a preparatory change for implementing nSVM-specific PGD switch (following nVMX' nested_vmx_load_cr3()), introduce nested_svm_load_cr3() instead of relying on kvm_set_cr3(). No functional change intended. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20200710141157.1640173-6-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-10KVM: nSVM: prepare to handle errors from enter_svm_guest_mode()Vitaly Kuznetsov
Some operations in enter_svm_guest_mode() may fail, e.g. currently we suppress kvm_set_cr3() return value. Prepare the code to proparate errors. No functional change intended. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20200710141157.1640173-5-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-10KVM: nSVM: reset nested_run_pending upon nested_svm_vmrun_msrpm() failureVitaly Kuznetsov
WARN_ON_ONCE(svm->nested.nested_run_pending) in nested_svm_vmexit() will fire if nested_run_pending remains '1' but it doesn't really need to, we are already failing and not going to run nested guest. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20200710141157.1640173-4-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-10KVM: nSVM: split kvm_init_shadow_npt_mmu() from kvm_init_shadow_mmu()Vitaly Kuznetsov
As a preparatory change for moving kvm_mmu_new_pgd() from nested_prepare_vmcb_save() to nested_svm_init_mmu_context() split kvm_init_shadow_npt_mmu() from kvm_init_shadow_mmu(). This also makes the code look more like nVMX (kvm_init_shadow_ept_mmu()). No functional change intended. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20200710141157.1640173-2-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-08KVM: nSVM: Check that MBZ bits in CR3 and CR4 are not set on vmrun of nested ↵Krish Sadhukhan
guests According to section "Canonicalization and Consistency Checks" in APM vol. 2 the following guest state is illegal: "Any MBZ bit of CR3 is set." "Any MBZ bit of CR4 is set." Suggeted-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> Message-Id: <1594168797-29444-3-git-send-email-krish.sadhukhan@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-08KVM: SVM: Add svm_ prefix to set/clr/is_intercept()Joerg Roedel
Make clear the symbols belong to the SVM code when they are built-in. No functional changes. Signed-off-by: Joerg Roedel <jroedel@suse.de> Message-Id: <20200625080325.28439-4-joro@8bytes.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-08KVM: SVM: Add vmcb_ prefix to mark_*() functionsJoerg Roedel
Make it more clear what data structure these functions operate on. No functional changes. Signed-off-by: Joerg Roedel <jroedel@suse.de> Message-Id: <20200625080325.28439-3-joro@8bytes.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-08KVM: nSVM: Check that DR6[63:32] and DR7[64:32] are not set on vmrun of ↵Krish Sadhukhan
nested guests According to section "Canonicalization and Consistency Checks" in APM vol. 2 the following guest state is illegal: "DR6[63:32] are not zero." "DR7[63:32] are not zero." "Any MBZ bit of EFER is set." Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> Message-Id: <20200522221954.32131-3-krish.sadhukhan@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-08KVM: SVM: fix calls to is_interceptPaolo Bonzini
is_intercept takes an INTERCEPT_* constant, not SVM_EXIT_*; because of this, the compiler was removing the body of the conditionals, as if is_intercept returned 0. This unveils a latent bug: when clearing the VINTR intercept, int_ctl must also be changed in the L1 VMCB (svm->nested.hsave), just like the intercept itself is also changed in the L1 VMCB. Otherwise V_IRQ remains set and, due to the VINTR intercept being clear, we get a spurious injection of a vector 0 interrupt on the next L2->L1 vmexit. Reported-by: Qian Cai <cai@lca.pw> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-01KVM: x86: extend struct kvm_vcpu_pv_apf_data with token infoVitaly Kuznetsov
Currently, APF mechanism relies on the #PF abuse where the token is being passed through CR2. If we switch to using interrupts to deliver page-ready notifications we need a different way to pass the data. Extent the existing 'struct kvm_vcpu_pv_apf_data' with token information for page-ready notifications. While on it, rename 'reason' to 'flags'. This doesn't change the semantics as we only have reasons '1' and '2' and these can be treated as bit flags but KVM_PV_REASON_PAGE_READY is going away with interrupt based delivery making 'reason' name misleading. The newly introduced apf_put_user_ready() temporary puts both flags and token information, this will be changed to put token only when we switch to interrupt based notifications. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20200525144125.143875-3-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-01KVM: nSVM: implement KVM_GET_NESTED_STATE and KVM_SET_NESTED_STATEPaolo Bonzini
Similar to VMX, the state that is captured through the currently available IOCTLs is a mix of L1 and L2 state, dependent on whether the L2 guest was running at the moment when the process was interrupted to save its state. In particular, the SVM-specific state for nested virtualization includes the L1 saved state (including the interrupt flag), the cached L2 controls, and the GIF. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-01KVM: MMU: pass arbitrary CR0/CR4/EFER to kvm_init_shadow_mmuPaolo Bonzini
This allows fetching the registers from the hsave area when setting up the NPT shadow MMU, and is needed for KVM_SET_NESTED_STATE (which runs long after the CR0, CR4 and EFER values in vcpu have been switched to hold L2 guest state). Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-01KVM: nSVM: leave guest mode when clearing EFER.SVMEPaolo Bonzini
According to the AMD manual, the effect of turning off EFER.SVME while a guest is running is undefined. We make it leave guest mode immediately, similar to the effect of clearing the VMX bit in MSR_IA32_FEAT_CTL. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-01KVM: nSVM: split nested_vmcb_check_controlsPaolo Bonzini
The authoritative state does not come from the VMCB once in guest mode, but KVM_SET_NESTED_STATE can still perform checks on L1's provided SVM controls because we get them from userspace. Therefore, split out a function to do them. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-01KVM: nSVM: remove HF_HIF_MASKPaolo Bonzini
The L1 flags can be found in the save area of svm->nested.hsave, fish it from there so that there is one fewer thing to migrate. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-01KVM: nSVM: remove HF_VINTR_MASKPaolo Bonzini
Now that the int_ctl field is stored in svm->nested.ctl.int_ctl, we can use it instead of vcpu->arch.hflags to check whether L2 is running in V_INTR_MASKING mode. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-01KVM: nSVM: synthesize correct EXITINTINFO on vmexitPaolo Bonzini
This bit was added to nested VMX right when nested_run_pending was introduced, but it is not yet there in nSVM. Since we can have pending events that L0 injected directly into L2 on vmentry, we have to transfer them into L1's queue. For this to work, one important change is required: svm_complete_interrupts (which clears the "injected" fields from the previous VMRUN, and updates them from svm->vmcb's EXITINTINFO) must be placed before we inject the vmexit. This is not too scary though; VMX even does it in vmx_vcpu_run. While at it, the nested_vmexit_inject tracepoint is moved towards the end of nested_svm_vmexit. This ensures that the synthesized EXITINTINFO is visible in the trace. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>