* [PATCH v7 1/2] KVM: x86/cpuid: generalize kvm_update_kvm_cpuid_base() and also capture limit
2023-01-06 10:35 [PATCH v7 0/2] KVM: x86/xen: update Xen CPUID Leaf 4 Paul Durrant
@ 2023-01-06 10:35 ` Paul Durrant
2023-01-11 10:00 ` David Woodhouse
2023-01-06 10:36 ` [PATCH v7 2/2] KVM: x86/xen: update Xen CPUID Leaf 4 (tsc info) sub-leaves, if present Paul Durrant
2023-01-19 20:48 ` [PATCH v7 0/2] KVM: x86/xen: update Xen CPUID Leaf 4 Sean Christopherson
2 siblings, 1 reply; 6+ messages in thread
From: Paul Durrant @ 2023-01-06 10:35 UTC (permalink / raw)
To: x86, kvm, xen-devel, linux-kernel
Cc: Paul Durrant, Sean Christopherson, Paolo Bonzini, Thomas Gleixner,
Ingo Molnar, Borislav Petkov, Dave Hansen, David Woodhouse
A subsequent patch will need to acquire the CPUID leaf range for emulated
Xen so explicitly pass the signature of the hypervisor we're interested in
to the new function. Also introduce a new kvm_hypervisor_cpuid structure
so we can neatly store both the base and limit leaf indices.
Signed-off-by: Paul Durrant <pdurrant@amazon.com>
---
Cc: Sean Christopherson <seanjc@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
v7:
- Morph kvm_update_hypervisor_cpuid() into kvm_get_hypervisor_cpuid()
- Place the definition of struct kvm_hypervisor_cpuid to avoid churn
in patch #2.
v6:
- New in this version
---
arch/x86/include/asm/kvm_host.h | 7 ++++++-
arch/x86/kvm/cpuid.c | 24 +++++++++++++-----------
2 files changed, 19 insertions(+), 12 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index c70690b2c82d..85cbe4571ac9 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -678,6 +678,11 @@ struct kvm_vcpu_hv {
} nested;
};
+struct kvm_hypervisor_cpuid {
+ u32 base;
+ u32 limit;
+};
+
/* Xen HVM per vcpu emulation context */
struct kvm_vcpu_xen {
u64 hypercall_rip;
@@ -826,7 +831,7 @@ struct kvm_vcpu_arch {
int cpuid_nent;
struct kvm_cpuid_entry2 *cpuid_entries;
- u32 kvm_cpuid_base;
+ struct kvm_hypervisor_cpuid kvm_cpuid;
u64 reserved_gpa_bits;
int maxphyaddr;
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 69768e4d53a6..db5a4d38fcd0 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -180,15 +180,15 @@ static int kvm_cpuid_check_equal(struct kvm_vcpu *vcpu, struct kvm_cpuid_entry2
return 0;
}
-static void kvm_update_kvm_cpuid_base(struct kvm_vcpu *vcpu)
+static struct kvm_hypervisor_cpuid kvm_get_hypervisor_cpuid(struct kvm_vcpu *vcpu,
+ const char *sig)
{
- u32 function;
+ struct kvm_hypervisor_cpuid cpuid = {};
struct kvm_cpuid_entry2 *entry;
+ u32 base;
- vcpu->arch.kvm_cpuid_base = 0;
-
- for_each_possible_hypervisor_cpuid_base(function) {
- entry = kvm_find_cpuid_entry(vcpu, function);
+ for_each_possible_hypervisor_cpuid_base(base) {
+ entry = kvm_find_cpuid_entry(vcpu, base);
if (entry) {
u32 signature[3];
@@ -197,19 +197,21 @@ static void kvm_update_kvm_cpuid_base(struct kvm_vcpu *vcpu)
signature[1] = entry->ecx;
signature[2] = entry->edx;
- BUILD_BUG_ON(sizeof(signature) > sizeof(KVM_SIGNATURE));
- if (!memcmp(signature, KVM_SIGNATURE, sizeof(signature))) {
- vcpu->arch.kvm_cpuid_base = function;
+ if (!memcmp(signature, sig, sizeof(signature))) {
+ cpuid.base = base;
+ cpuid.limit = entry->eax;
break;
}
}
}
+
+ return cpuid;
}
static struct kvm_cpuid_entry2 *__kvm_find_kvm_cpuid_features(struct kvm_vcpu *vcpu,
struct kvm_cpuid_entry2 *entries, int nent)
{
- u32 base = vcpu->arch.kvm_cpuid_base;
+ u32 base = vcpu->arch.kvm_cpuid.base;
if (!base)
return NULL;
@@ -439,7 +441,7 @@ static int kvm_set_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid_entry2 *e2,
vcpu->arch.cpuid_entries = e2;
vcpu->arch.cpuid_nent = nent;
- kvm_update_kvm_cpuid_base(vcpu);
+ vcpu->arch.kvm_cpuid = kvm_get_hypervisor_cpuid(vcpu, KVM_SIGNATURE);
kvm_vcpu_after_set_cpuid(vcpu);
return 0;
--
2.20.1
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH v7 2/2] KVM: x86/xen: update Xen CPUID Leaf 4 (tsc info) sub-leaves, if present
2023-01-06 10:35 [PATCH v7 0/2] KVM: x86/xen: update Xen CPUID Leaf 4 Paul Durrant
2023-01-06 10:35 ` [PATCH v7 1/2] KVM: x86/cpuid: generalize kvm_update_kvm_cpuid_base() and also capture limit Paul Durrant
@ 2023-01-06 10:36 ` Paul Durrant
2023-01-11 10:00 ` David Woodhouse
2023-01-19 20:48 ` [PATCH v7 0/2] KVM: x86/xen: update Xen CPUID Leaf 4 Sean Christopherson
2 siblings, 1 reply; 6+ messages in thread
From: Paul Durrant @ 2023-01-06 10:36 UTC (permalink / raw)
To: x86, kvm, xen-devel, linux-kernel
Cc: Paul Durrant, Sean Christopherson, Paolo Bonzini, Juergen Gross,
Boris Ostrovsky, Thomas Gleixner, Ingo Molnar, Borislav Petkov,
Dave Hansen, H. Peter Anvin, David Woodhouse
The scaling information in subleaf 1 should match the values set by KVM in
the 'vcpu_info' sub-structure 'time_info' (a.k.a. pvclock_vcpu_time_info)
which is shared with the guest, but is not directly available to the VMM.
The offset values are not set since a TSC offset is already applied.
The TSC frequency should also be set in sub-leaf 2.
Signed-off-by: Paul Durrant <pdurrant@amazon.com>
---
Cc: Sean Christopherson <seanjc@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: David Woodhouse <dwmw2@infradead.org>
v7:
- Add a definition of XEN_SIGNATURE into asm/xen/hypervisor.h
and use that
v6:
- Stash Xen cpuid base and limit values when cpuid is set
- Re-name kvm_xen_setup_tsc_info() to kvm_xen_update_tsc_info()
v5:
- Drop the caching of the CPUID entry pointers and only update the
sub-leaves if the CPU frequency has actually changed
v4:
- Update commit comment
v3:
- Add leaf limit check in kvm_xen_set_cpuid()
v2:
- Make sure sub-leaf pointers are NULLed if the time leaf is removed
---
arch/x86/include/asm/kvm_host.h | 1 +
arch/x86/include/asm/xen/hypervisor.h | 4 +++-
arch/x86/kvm/cpuid.c | 2 ++
arch/x86/kvm/x86.c | 1 +
arch/x86/kvm/xen.c | 26 ++++++++++++++++++++++++++
arch/x86/kvm/xen.h | 7 +++++++
6 files changed, 40 insertions(+), 1 deletion(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 85cbe4571ac9..f3e9f6e4b3ea 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -703,6 +703,7 @@ struct kvm_vcpu_xen {
struct hrtimer timer;
int poll_evtchn;
struct timer_list poll_timer;
+ struct kvm_hypervisor_cpuid cpuid;
};
struct kvm_queued_exception {
diff --git a/arch/x86/include/asm/xen/hypervisor.h b/arch/x86/include/asm/xen/hypervisor.h
index 16f548a661cf..5fc35f889cd1 100644
--- a/arch/x86/include/asm/xen/hypervisor.h
+++ b/arch/x86/include/asm/xen/hypervisor.h
@@ -38,9 +38,11 @@ extern struct start_info *xen_start_info;
#include <asm/processor.h>
+#define XEN_SIGNATURE "XenVMMXenVMM"
+
static inline uint32_t xen_cpuid_base(void)
{
- return hypervisor_cpuid_base("XenVMMXenVMM", 2);
+ return hypervisor_cpuid_base(XEN_SIGNATURE, 2);
}
struct pci_dev;
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index db5a4d38fcd0..560f880cc9fd 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -25,6 +25,7 @@
#include "mmu.h"
#include "trace.h"
#include "pmu.h"
+#include "xen.h"
/*
* Unlike "struct cpuinfo_x86.x86_capability", kvm_cpu_caps doesn't need to be
@@ -442,6 +443,7 @@ static int kvm_set_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid_entry2 *e2,
vcpu->arch.cpuid_nent = nent;
vcpu->arch.kvm_cpuid = kvm_get_hypervisor_cpuid(vcpu, KVM_SIGNATURE);
+ vcpu->arch.xen.cpuid = kvm_get_hypervisor_cpuid(vcpu, XEN_SIGNATURE);
kvm_vcpu_after_set_cpuid(vcpu);
return 0;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index f6ef44dc8a0e..e849a5445cac 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3158,6 +3158,7 @@ static int kvm_guest_time_update(struct kvm_vcpu *v)
&vcpu->hv_clock.tsc_shift,
&vcpu->hv_clock.tsc_to_system_mul);
vcpu->hw_tsc_khz = tgt_tsc_khz;
+ kvm_xen_update_tsc_info(v);
}
vcpu->hv_clock.tsc_timestamp = tsc_timestamp;
diff --git a/arch/x86/kvm/xen.c b/arch/x86/kvm/xen.c
index 2e29bdc2949c..fbfc7c17defd 100644
--- a/arch/x86/kvm/xen.c
+++ b/arch/x86/kvm/xen.c
@@ -22,6 +22,9 @@
#include <xen/interface/event_channel.h>
#include <xen/interface/sched.h>
+#include <asm/xen/cpuid.h>
+
+#include "cpuid.h"
#include "trace.h"
static int kvm_xen_set_evtchn(struct kvm_xen_evtchn *xe, struct kvm *kvm);
@@ -2067,6 +2070,29 @@ void kvm_xen_destroy_vcpu(struct kvm_vcpu *vcpu)
del_timer_sync(&vcpu->arch.xen.poll_timer);
}
+void kvm_xen_update_tsc_info(struct kvm_vcpu *vcpu)
+{
+ struct kvm_cpuid_entry2 *entry;
+ u32 function;
+
+ if (!vcpu->arch.xen.cpuid.base)
+ return;
+
+ function = vcpu->arch.xen.cpuid.base | XEN_CPUID_LEAF(3);
+ if (function > vcpu->arch.xen.cpuid.limit)
+ return;
+
+ entry = kvm_find_cpuid_entry_index(vcpu, function, 1);
+ if (entry) {
+ entry->ecx = vcpu->arch.hv_clock.tsc_to_system_mul;
+ entry->edx = vcpu->arch.hv_clock.tsc_shift;
+ }
+
+ entry = kvm_find_cpuid_entry_index(vcpu, function, 2);
+ if (entry)
+ entry->eax = vcpu->arch.hw_tsc_khz;
+}
+
void kvm_xen_init_vm(struct kvm *kvm)
{
idr_init(&kvm->arch.xen.evtchn_ports);
diff --git a/arch/x86/kvm/xen.h b/arch/x86/kvm/xen.h
index ea33d80a0c51..f8f1fe22d090 100644
--- a/arch/x86/kvm/xen.h
+++ b/arch/x86/kvm/xen.h
@@ -9,6 +9,8 @@
#ifndef __ARCH_X86_KVM_XEN_H__
#define __ARCH_X86_KVM_XEN_H__
+#include <asm/xen/hypervisor.h>
+
#ifdef CONFIG_KVM_XEN
#include <linux/jump_label_ratelimit.h>
@@ -32,6 +34,7 @@ int kvm_xen_set_evtchn_fast(struct kvm_xen_evtchn *xe,
int kvm_xen_setup_evtchn(struct kvm *kvm,
struct kvm_kernel_irq_routing_entry *e,
const struct kvm_irq_routing_entry *ue);
+void kvm_xen_update_tsc_info(struct kvm_vcpu *vcpu);
static inline bool kvm_xen_msr_enabled(struct kvm *kvm)
{
@@ -135,6 +138,10 @@ static inline bool kvm_xen_timer_enabled(struct kvm_vcpu *vcpu)
{
return false;
}
+
+static inline void kvm_xen_update_tsc_info(struct kvm_vcpu *vcpu)
+{
+}
#endif
int kvm_xen_hypercall(struct kvm_vcpu *vcpu);
--
2.20.1
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH v7 0/2] KVM: x86/xen: update Xen CPUID Leaf 4
2023-01-06 10:35 [PATCH v7 0/2] KVM: x86/xen: update Xen CPUID Leaf 4 Paul Durrant
2023-01-06 10:35 ` [PATCH v7 1/2] KVM: x86/cpuid: generalize kvm_update_kvm_cpuid_base() and also capture limit Paul Durrant
2023-01-06 10:36 ` [PATCH v7 2/2] KVM: x86/xen: update Xen CPUID Leaf 4 (tsc info) sub-leaves, if present Paul Durrant
@ 2023-01-19 20:48 ` Sean Christopherson
2 siblings, 0 replies; 6+ messages in thread
From: Sean Christopherson @ 2023-01-19 20:48 UTC (permalink / raw)
To: Sean Christopherson, x86, kvm, xen-devel, linux-kernel,
Paul Durrant
Cc: Borislav Petkov, Boris Ostrovsky, Dave Hansen, David Woodhouse,
H. Peter Anvin, Ingo Molnar, Juergen Gross, Paolo Bonzini,
Thomas Gleixner
On Fri, 06 Jan 2023 10:35:58 +0000, Paul Durrant wrote:
> Patch #2 was the original patch. It has been expended to a series in v6.
>
> Paul Durrant (2):
> KVM: x86/cpuid: generalize kvm_update_kvm_cpuid_base() and also
> capture limit
> KVM: x86/xen: update Xen CPUID Leaf 4 (tsc info) sub-leaves, if
> present
>
> [...]
Applied to kvm-x86 misc, thanks!
[1/2] KVM: x86/cpuid: generalize kvm_update_kvm_cpuid_base() and also capture limit
https://github.com/kvm-x86/linux/commit/e3ac476711ca
[2/2] KVM: x86/xen: update Xen CPUID Leaf 4 (tsc info) sub-leaves, if present
https://github.com/kvm-x86/linux/commit/509d19565173
--
https://github.com/kvm-x86/linux/tree/next
https://github.com/kvm-x86/linux/tree/fixes
^ permalink raw reply [flat|nested] 6+ messages in thread