From: Yang Weijiang <weijiang.yang@intel.com>
To: pbonzini@redhat.com, rkrcmar@redhat.com,
sean.j.christopherson@intel.com, jmattson@google.com,
linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
mst@redhat.com, yu-cheng.yu@intel.com
Cc: Yang Weijiang <weijiang.yang@intel.com>
Subject: [PATCH v3 8/8] KVM:X86: Add user-space read/write interface for CET MSRs.
Date: Mon, 25 Feb 2019 21:27:16 +0800 [thread overview]
Message-ID: <20190225132716.6982-9-weijiang.yang@intel.com> (raw)
In-Reply-To: <20190225132716.6982-1-weijiang.yang@intel.com>
The Guest MSRs are stored in fpu storage area, they are
operated by XSAVES/XRSTORS, so use kvm_load_guest_fpu
to restore them is a convenient way to let KVM access
them. After finish operation, need to restore Host MSR
contents by kvm_put_guest_fpu.
Signed-off-by: Yang Weijiang <weijiang.yang@intel.com>
---
arch/x86/kvm/x86.c | 46 +++++++++++++++++++++++++++++++++++++++++++---
1 file changed, 43 insertions(+), 3 deletions(-)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index a0f8b71b2132..a4bdbef3a712 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -75,6 +75,8 @@
#define MAX_IO_MSRS 256
#define KVM_MAX_MCE_BANKS 32
+#define MAX_GUEST_CET_MSRS 5
+
u64 __read_mostly kvm_mce_cap_supported = MCG_CTL_P | MCG_SER_P;
EXPORT_SYMBOL_GPL(kvm_mce_cap_supported);
@@ -214,6 +216,8 @@ struct kvm_stats_debugfs_item debugfs_entries[] = {
u64 __read_mostly host_xcr0;
static int emulator_fix_hypercall(struct x86_emulate_ctxt *ctxt);
+static void kvm_load_guest_fpu(struct kvm_vcpu *vcpu);
+static void kvm_put_guest_fpu(struct kvm_vcpu *vcpu);
static inline void kvm_async_pf_hash_reset(struct kvm_vcpu *vcpu)
{
@@ -2889,21 +2893,57 @@ int kvm_get_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
}
EXPORT_SYMBOL_GPL(kvm_get_msr_common);
+static int do_cet_msrs(struct kvm_vcpu *vcpu, int entry_num,
+ struct kvm_msr_entry *entries, bool read)
+{
+ int i = entry_num;
+ int j = MAX_GUEST_CET_MSRS;
+ bool has_cet;
+
+ has_cet = guest_cpuid_has(vcpu, X86_FEATURE_SHSTK) |
+ guest_cpuid_has(vcpu, X86_FEATURE_IBT);
+ /*
+ * Guest CET MSRs are saved by XSAVES, so need to restore
+ * them first, then read out or update the contents and
+ * restore Host ones.
+ */
+ if (has_cet) {
+ kvm_load_guest_fpu(vcpu);
+
+ if (read) {
+ for (j = 0; j < MAX_GUEST_CET_MSRS; j++, i++)
+ rdmsrl(entries[i].index, entries[i].data);
+ } else {
+ for (j = 0; j < MAX_GUEST_CET_MSRS; j++, i++)
+ wrmsrl(entries[i].index, entries[i].data);
+ }
+
+ kvm_put_guest_fpu(vcpu);
+ }
+ return j;
+}
/*
* Read or write a bunch of msrs. All parameters are kernel addresses.
*
* @return number of msrs set successfully.
*/
static int __msr_io(struct kvm_vcpu *vcpu, struct kvm_msrs *msrs,
- struct kvm_msr_entry *entries,
+ struct kvm_msr_entry *entries, bool read,
int (*do_msr)(struct kvm_vcpu *vcpu,
unsigned index, u64 *data))
{
int i;
- for (i = 0; i < msrs->nmsrs; ++i)
+ for (i = 0; i < msrs->nmsrs; ++i) {
+ /* If it comes to CET related MSRs, read them together. */
+ if (entries[i].index == MSR_IA32_U_CET) {
+ i += do_cet_msrs(vcpu, i, entries, read) - 1;
+ continue;
+ }
+
if (do_msr(vcpu, entries[i].index, &entries[i].data))
break;
+ }
return i;
}
@@ -2938,7 +2978,7 @@ static int msr_io(struct kvm_vcpu *vcpu, struct kvm_msrs __user *user_msrs,
goto out;
}
- r = n = __msr_io(vcpu, &msrs, entries, do_msr);
+ r = n = __msr_io(vcpu, &msrs, entries, !!writeback, do_msr);
if (r < 0)
goto out_free;
--
2.17.1
next prev parent reply other threads:[~2019-02-26 6:33 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-25 13:27 [PATCH v3 0/8] This patch-set is to enable Guest CET support Yang Weijiang
2019-02-25 13:27 ` [PATCH v3 1/8] KVM:VMX: Define CET VMCS fields and bits Yang Weijiang
2019-02-26 19:31 ` Jim Mattson
2019-02-26 7:52 ` Yang Weijiang
2019-02-28 15:53 ` Sean Christopherson
2019-02-28 9:51 ` Yang Weijiang
2019-02-25 13:27 ` [PATCH v3 2/8] KVM:CPUID: Define CET CPUID bits and CR4.CET master enable bit Yang Weijiang
2019-02-26 19:48 ` Jim Mattson
2019-02-26 7:57 ` Yang Weijiang
2019-03-01 2:15 ` Xiaoyao Li
2019-02-28 16:04 ` Sean Christopherson
2019-02-28 8:10 ` Yang Weijiang
2019-02-25 13:27 ` [PATCH v3 3/8] KVM:CPUID: Add CPUID support for Guest CET Yang Weijiang
2019-02-28 15:59 ` Sean Christopherson
2019-02-28 8:28 ` Yang Weijiang
2019-03-01 14:53 ` Sean Christopherson
2019-03-03 9:36 ` Yang Weijiang
2019-03-04 18:28 ` Sean Christopherson
2019-03-04 12:17 ` Yang Weijiang
2019-03-04 18:47 ` Sean Christopherson
2019-03-04 10:01 ` Yang Weijiang
2019-03-04 18:54 ` Sean Christopherson
2019-03-04 10:11 ` Yang Weijiang
2019-03-08 11:32 ` Paolo Bonzini
2019-03-10 12:18 ` Yang Weijiang
2019-02-25 13:27 ` [PATCH v3 4/8] KVM:CPUID: Fix xsaves area size calculation for CPUID.(EAX=0xD,ECX=1) Yang Weijiang
2019-02-25 13:27 ` [PATCH v3 5/8] KVM:VMX: Pass through host CET related MSRs to Guest Yang Weijiang
2019-03-04 18:53 ` Sean Christopherson
2019-03-04 10:07 ` Yang Weijiang
2019-03-05 3:21 ` Sean Christopherson
2019-02-25 13:27 ` [PATCH v3 6/8] KVM:VMX: Load Guest CET via VMCS when CET is enabled in Guest Yang Weijiang
2019-02-28 16:17 ` Sean Christopherson
2019-02-28 8:38 ` Yang Weijiang
2019-03-01 14:58 ` Sean Christopherson
2019-03-03 12:26 ` Yang Weijiang
2019-03-04 18:43 ` Sean Christopherson
2019-03-04 9:56 ` Yang Weijiang
2019-03-05 3:12 ` Sean Christopherson
2019-03-04 12:36 ` Yang Weijiang
2019-03-08 16:28 ` Sean Christopherson
2019-03-08 16:36 ` Paolo Bonzini
2019-02-25 13:27 ` [PATCH v3 7/8] KVM:X86: Add XSS bit 11 and 12 support for CET xsaves/xrstors Yang Weijiang
2019-02-28 16:25 ` Sean Christopherson
2019-02-28 8:44 ` Yang Weijiang
2019-03-08 11:32 ` Paolo Bonzini
2019-03-10 12:20 ` Yang Weijiang
2019-03-10 13:35 ` Yang Weijiang
2019-03-11 15:32 ` Paolo Bonzini
2019-03-12 14:30 ` Yang Weijiang
2019-03-08 10:49 ` Paolo Bonzini
2019-03-11 1:29 ` Kang, Luwei
2019-02-25 13:27 ` Yang Weijiang [this message]
2019-02-28 16:32 ` [PATCH v3 8/8] KVM:X86: Add user-space read/write interface for CET MSRs Sean Christopherson
2019-02-28 9:41 ` Yang Weijiang
2019-03-08 17:30 ` Sean Christopherson
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