From: Yang Weijiang <weijiang.yang@intel.com>
To: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Yang Weijiang <weijiang.yang@intel.com>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
pbonzini@redhat.com, jmattson@google.com,
yu.c.zhang@linux.intel.com
Subject: Re: [PATCH v11 8/9] KVM: VMX: Enable CET support for nested VM
Date: Fri, 24 Apr 2020 23:24:19 +0800 [thread overview]
Message-ID: <20200424152419.GL24039@local-michael-cet-test> (raw)
In-Reply-To: <20200423182906.GL17824@linux.intel.com>
On Thu, Apr 23, 2020 at 11:29:06AM -0700, Sean Christopherson wrote:
> On Thu, Mar 26, 2020 at 04:18:45PM +0800, Yang Weijiang wrote:
> > CET MSRs pass through guests for performance consideration.
> > Configure the MSRs to match L0/L1 settings so that nested VM
> > is able to run with CET.
> >
> > Signed-off-by: Yang Weijiang <weijiang.yang@intel.com>
> > ---
> > arch/x86/kvm/vmx/nested.c | 41 +++++++++++++++++++++++++++++++++++++--
> > arch/x86/kvm/vmx/vmcs12.c | 6 ++++++
> > arch/x86/kvm/vmx/vmcs12.h | 14 ++++++++++++-
> > arch/x86/kvm/vmx/vmx.c | 1 +
> > 4 files changed, 59 insertions(+), 3 deletions(-)
> >
> > diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
> > index e47eb7c0fbae..a71ef33de55f 100644
> > --- a/arch/x86/kvm/vmx/nested.c
> > +++ b/arch/x86/kvm/vmx/nested.c
> > @@ -627,6 +627,41 @@ static inline bool nested_vmx_prepare_msr_bitmap(struct kvm_vcpu *vcpu,
> > nested_vmx_disable_intercept_for_msr(msr_bitmap_l1, msr_bitmap_l0,
> > MSR_KERNEL_GS_BASE, MSR_TYPE_RW);
> >
> > + /* Pass CET MSRs to nested VM if L0 and L1 are set to pass-through. */
> > + if (!msr_write_intercepted_l01(vcpu, MSR_IA32_U_CET))
> > + nested_vmx_disable_intercept_for_msr(
> > + msr_bitmap_l1, msr_bitmap_l0,
> > + MSR_IA32_U_CET, MSR_TYPE_RW);
> > +
> > + if (!msr_write_intercepted_l01(vcpu, MSR_IA32_PL3_SSP))
> > + nested_vmx_disable_intercept_for_msr(
> > + msr_bitmap_l1, msr_bitmap_l0,
> > + MSR_IA32_PL3_SSP, MSR_TYPE_RW);
> > +
> > + if (!msr_write_intercepted_l01(vcpu, MSR_IA32_S_CET))
> > + nested_vmx_disable_intercept_for_msr(
> > + msr_bitmap_l1, msr_bitmap_l0,
> > + MSR_IA32_S_CET, MSR_TYPE_RW);
> > +
> > + if (!msr_write_intercepted_l01(vcpu, MSR_IA32_PL0_SSP))
> > + nested_vmx_disable_intercept_for_msr(
> > + msr_bitmap_l1, msr_bitmap_l0,
> > + MSR_IA32_PL0_SSP, MSR_TYPE_RW);
> > +
> > + if (!msr_write_intercepted_l01(vcpu, MSR_IA32_PL1_SSP))
> > + nested_vmx_disable_intercept_for_msr(
> > + msr_bitmap_l1, msr_bitmap_l0,
> > + MSR_IA32_PL1_SSP, MSR_TYPE_RW);
> > +
> > + if (!msr_write_intercepted_l01(vcpu, MSR_IA32_PL2_SSP))
> > + nested_vmx_disable_intercept_for_msr(
> > + msr_bitmap_l1, msr_bitmap_l0,
> > + MSR_IA32_PL2_SSP, MSR_TYPE_RW);
> > +
> > + if (!msr_write_intercepted_l01(vcpu, MSR_IA32_INT_SSP_TAB))
> > + nested_vmx_disable_intercept_for_msr(
> > + msr_bitmap_l1, msr_bitmap_l0,
> > + MSR_IA32_INT_SSP_TAB, MSR_TYPE_RW);
>
> That's a lot of copy-paste. Maybe add a helper to do the conditional l01
> check and subsequent call to nested_vmx_disable_intercept_for_msr()? It's
> still a lot of boilerplate, but it's at least a little better. Not sure
> what a good name would be.
>
> nested_vmx_update_intercept_for_msr(vcpu, MSR_IA32_U_CET,
> msr_bitmap_l1, msr_bitmap_l0,
> MSR_TYPE_RW);
>
OK, I'll figure out how to make it nicer :-)
>
> > /*
> > * Checking the L0->L1 bitmap is trying to verify two things:
> > *
> > @@ -6040,7 +6075,8 @@ void nested_vmx_setup_ctls_msrs(struct nested_vmx_msrs *msrs, u32 ept_caps)
> > msrs->exit_ctls_high |=
> > VM_EXIT_ALWAYSON_WITHOUT_TRUE_MSR |
> > VM_EXIT_LOAD_IA32_EFER | VM_EXIT_SAVE_IA32_EFER |
> > - VM_EXIT_SAVE_VMX_PREEMPTION_TIMER | VM_EXIT_ACK_INTR_ON_EXIT;
> > + VM_EXIT_SAVE_VMX_PREEMPTION_TIMER | VM_EXIT_ACK_INTR_ON_EXIT |
> > + VM_EXIT_LOAD_HOST_CET_STATE;
> >
> > /* We support free control of debug control saving. */
> > msrs->exit_ctls_low &= ~VM_EXIT_SAVE_DEBUG_CONTROLS;
> > @@ -6057,7 +6093,8 @@ void nested_vmx_setup_ctls_msrs(struct nested_vmx_msrs *msrs, u32 ept_caps)
> > #endif
> > VM_ENTRY_LOAD_IA32_PAT;
> > msrs->entry_ctls_high |=
> > - (VM_ENTRY_ALWAYSON_WITHOUT_TRUE_MSR | VM_ENTRY_LOAD_IA32_EFER);
> > + (VM_ENTRY_ALWAYSON_WITHOUT_TRUE_MSR | VM_ENTRY_LOAD_IA32_EFER |
> > + VM_ENTRY_LOAD_GUEST_CET_STATE);
>
> This is wrong, the OR path is only for emulated stuff, I'm guessing you're
> not planning on emulating CET :-)
When I tested nested VM, if it's not "ORed" here, nested VM entry will
fail, so what's your suggestion on this?
>
> And I think this needs to be conditional based on supported_xss?
Yes, a check is necessary.
>
> > /* We support free control of debug control loading. */
> > msrs->entry_ctls_low &= ~VM_ENTRY_LOAD_DEBUG_CONTROLS;
> > diff --git a/arch/x86/kvm/vmx/vmcs12.c b/arch/x86/kvm/vmx/vmcs12.c
> > index 53dfb401316d..82b82bebeee0 100644
> > --- a/arch/x86/kvm/vmx/vmcs12.c
> > +++ b/arch/x86/kvm/vmx/vmcs12.c
> > @@ -141,6 +141,9 @@ const unsigned short vmcs_field_to_offset_table[] = {
> > FIELD(GUEST_PENDING_DBG_EXCEPTIONS, guest_pending_dbg_exceptions),
> > FIELD(GUEST_SYSENTER_ESP, guest_sysenter_esp),
> > FIELD(GUEST_SYSENTER_EIP, guest_sysenter_eip),
> > + FIELD(GUEST_S_CET, guest_s_cet),
> > + FIELD(GUEST_SSP, guest_ssp),
> > + FIELD(GUEST_INTR_SSP_TABLE, guest_ssp_tbl),
> > FIELD(HOST_CR0, host_cr0),
> > FIELD(HOST_CR3, host_cr3),
> > FIELD(HOST_CR4, host_cr4),
> > @@ -153,5 +156,8 @@ const unsigned short vmcs_field_to_offset_table[] = {
> > FIELD(HOST_IA32_SYSENTER_EIP, host_ia32_sysenter_eip),
> > FIELD(HOST_RSP, host_rsp),
> > FIELD(HOST_RIP, host_rip),
> > + FIELD(HOST_S_CET, host_s_cet),
> > + FIELD(HOST_SSP, host_ssp),
> > + FIELD(HOST_INTR_SSP_TABLE, host_ssp_tbl),
> > };
> > const unsigned int nr_vmcs12_fields = ARRAY_SIZE(vmcs_field_to_offset_table);
> > diff --git a/arch/x86/kvm/vmx/vmcs12.h b/arch/x86/kvm/vmx/vmcs12.h
> > index d0c6df373f67..62b7be68f05c 100644
> > --- a/arch/x86/kvm/vmx/vmcs12.h
> > +++ b/arch/x86/kvm/vmx/vmcs12.h
> > @@ -118,7 +118,13 @@ struct __packed vmcs12 {
> > natural_width host_ia32_sysenter_eip;
> > natural_width host_rsp;
> > natural_width host_rip;
> > - natural_width paddingl[8]; /* room for future expansion */
> > + natural_width host_s_cet;
> > + natural_width host_ssp;
> > + natural_width host_ssp_tbl;
> > + natural_width guest_s_cet;
> > + natural_width guest_ssp;
> > + natural_width guest_ssp_tbl;
> > + natural_width paddingl[2]; /* room for future expansion */
>
> Tangetial topic, it'd be helpful if FIELD and FIELD64 had compile-time
> assertions similar to vmcs_read*() to verify the size of the vmcs12 field
> is correct. In other words, I don't feel like reviewing all of these :-).
>
OK, let me figure out how to polish them...
> > u32 pin_based_vm_exec_control;
> > u32 cpu_based_vm_exec_control;
> > u32 exception_bitmap;
> > @@ -301,6 +307,12 @@ static inline void vmx_check_vmcs12_offsets(void)
> > CHECK_OFFSET(host_ia32_sysenter_eip, 656);
> > CHECK_OFFSET(host_rsp, 664);
> > CHECK_OFFSET(host_rip, 672);
> > + CHECK_OFFSET(host_s_cet, 680);
> > + CHECK_OFFSET(host_ssp, 688);
> > + CHECK_OFFSET(host_ssp_tbl, 696);
> > + CHECK_OFFSET(guest_s_cet, 704);
> > + CHECK_OFFSET(guest_ssp, 712);
> > + CHECK_OFFSET(guest_ssp_tbl, 720);
> > CHECK_OFFSET(pin_based_vm_exec_control, 744);
> > CHECK_OFFSET(cpu_based_vm_exec_control, 748);
> > CHECK_OFFSET(exception_bitmap, 752);
> > diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
> > index a3d01014b9e7..c2e950d378bd 100644
> > --- a/arch/x86/kvm/vmx/vmx.c
> > +++ b/arch/x86/kvm/vmx/vmx.c
> > @@ -7153,6 +7153,7 @@ static void nested_vmx_cr_fixed1_bits_update(struct kvm_vcpu *vcpu)
> > cr4_fixed1_update(X86_CR4_PKE, ecx, feature_bit(PKU));
> > cr4_fixed1_update(X86_CR4_UMIP, ecx, feature_bit(UMIP));
> > cr4_fixed1_update(X86_CR4_LA57, ecx, feature_bit(LA57));
> > + cr4_fixed1_update(X86_CR4_CET, ecx, feature_bit(SHSTK));
> >
> > #undef cr4_fixed1_update
> > }
> > --
> > 2.17.2
> >
next prev parent reply other threads:[~2020-04-24 15:22 UTC|newest]
Thread overview: 57+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-26 8:18 [PATCH v11 0/9] Introduce support for guest CET feature Yang Weijiang
2020-03-26 8:18 ` [PATCH v11 1/9] KVM: VMX: Introduce CET VMX fields and flags Yang Weijiang
2020-04-23 16:07 ` Sean Christopherson
2020-04-24 13:39 ` Yang Weijiang
2020-04-23 16:39 ` Sean Christopherson
2020-04-24 13:44 ` Yang Weijiang
2020-03-26 8:18 ` [PATCH v11 2/9] KVM: VMX: Set guest CET MSRs per KVM and host configuration Yang Weijiang
2020-04-23 16:27 ` Sean Christopherson
2020-04-24 14:07 ` Yang Weijiang
2020-04-24 14:55 ` Sean Christopherson
2020-04-25 9:14 ` Yang Weijiang
2020-04-25 13:26 ` Paolo Bonzini
2020-04-26 15:26 ` Yang Weijiang
2020-03-26 8:18 ` [PATCH v11 3/9] KVM: VMX: Set host/guest CET states for vmexit/vmentry Yang Weijiang
2020-04-01 2:23 ` kbuild test robot
2020-04-23 17:17 ` Sean Christopherson
2020-04-24 14:35 ` Yang Weijiang
2020-04-24 14:49 ` Sean Christopherson
2020-04-25 9:20 ` Yang Weijiang
2020-04-27 17:04 ` Sean Christopherson
2020-04-27 17:56 ` Sean Christopherson
2020-03-26 8:18 ` [PATCH v11 4/9] KVM: VMX: Check CET dependencies on CR settings Yang Weijiang
2020-04-23 17:20 ` Sean Christopherson
2020-04-24 14:36 ` Yang Weijiang
2020-03-26 8:18 ` [PATCH v11 5/9] KVM: X86: Refresh CPUID once guest XSS MSR changes Yang Weijiang
2020-04-01 3:50 ` kbuild test robot
2020-04-23 17:34 ` Sean Christopherson
2020-04-24 14:47 ` Yang Weijiang
2020-04-25 13:19 ` Paolo Bonzini
2020-04-26 15:01 ` Yang Weijiang
2020-03-26 8:18 ` [PATCH v11 6/9] KVM: X86: Load guest fpu state when access MSRs managed by XSAVES Yang Weijiang
2020-03-26 8:18 ` [PATCH v11 7/9] KVM: X86: Add userspace access interface for CET MSRs Yang Weijiang
2020-03-28 7:40 ` kbuild test robot
2020-04-01 4:54 ` kbuild test robot
2020-04-23 18:14 ` Sean Christopherson
2020-04-24 15:02 ` Yang Weijiang
2020-04-24 15:10 ` Sean Christopherson
2020-04-25 9:28 ` Yang Weijiang
2020-04-25 15:31 ` Paolo Bonzini
2020-04-26 15:23 ` Yang Weijiang
2020-04-27 14:04 ` Paolo Bonzini
2020-04-28 13:41 ` Yang Weijiang
2020-03-26 8:18 ` [PATCH v11 8/9] KVM: VMX: Enable CET support for nested VM Yang Weijiang
2020-04-01 6:11 ` kbuild test robot
2020-04-23 18:29 ` Sean Christopherson
2020-04-24 15:24 ` Yang Weijiang [this message]
2020-03-26 8:18 ` [PATCH v11 9/9] KVM: X86: Set CET feature bits for CPUID enumeration Yang Weijiang
2020-03-27 4:41 ` kbuild test robot
2020-04-23 16:56 ` Sean Christopherson
2020-04-24 14:17 ` Yang Weijiang
2020-04-23 16:58 ` Sean Christopherson
2020-04-24 14:23 ` Yang Weijiang
2020-03-26 8:18 ` [kvm-unit-tests PATCH] x86: Add tests for user-mode CET Yang Weijiang
2020-04-23 15:51 ` [PATCH v11 0/9] Introduce support for guest CET feature Sean Christopherson
2020-04-24 13:31 ` Yang Weijiang
2020-04-23 16:03 ` Sean Christopherson
2020-04-24 13:34 ` Yang Weijiang
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200424152419.GL24039@local-michael-cet-test \
--to=weijiang.yang@intel.com \
--cc=jmattson@google.com \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=pbonzini@redhat.com \
--cc=sean.j.christopherson@intel.com \
--cc=yu.c.zhang@linux.intel.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).