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: 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>
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 | 11 ++++++-----
arch/x86/kvm/cpuid.c | 2 ++
arch/x86/kvm/x86.c | 1 +
arch/x86/kvm/xen.c | 26 ++++++++++++++++++++++++++
arch/x86/kvm/xen.h | 7 +++++++
5 files changed, 42 insertions(+), 5 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index ff201ad35551..44329594bdf7 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;
@@ -698,6 +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 {
@@ -710,11 +716,6 @@ struct kvm_queued_exception {
bool has_payload;
};
-struct kvm_hypervisor_cpuid {
- u32 base;
- u32 limit;
-};
-
struct kvm_vcpu_arch {
/*
* rip and regs accesses must go through
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 2468720f8d84..e661413ddf8d 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
@@ -441,6 +442,7 @@ static int kvm_set_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid_entry2 *e2,
vcpu->arch.cpuid_nent = nent;
kvm_update_hypervisor_cpuid(vcpu, KVM_SIGNATURE, &vcpu->arch.kvm_cpuid);
+ kvm_update_hypervisor_cpuid(vcpu, XEN_SIGNATURE, &vcpu->arch.xen.cpuid);
kvm_vcpu_after_set_cpuid(vcpu);
return 0;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index fd6c01a39312..60acc55f0c00 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 d7af40240248..46297521791c 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);
@@ -2061,6 +2064,29 @@ 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..88dd085e10f8 100644
--- a/arch/x86/kvm/xen.h
+++ b/arch/x86/kvm/xen.h
@@ -32,6 +32,7 @@ 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 +136,10 @@ 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);
@@ -143,6 +148,8 @@ int kvm_xen_hypercall(struct kvm_vcpu *vcpu);
#include <asm/xen/interface.h>
#include <xen/interface/vcpu.h>
+#define XEN_SIGNATURE "XenVMMXenVMM"
+
void kvm_xen_update_runstate(struct kvm_vcpu *vcpu, int state);
static inline void kvm_xen_runstate_set_running(struct kvm_vcpu *vcpu)
--
2.20.1On Tue, Dec 20, 2022, Paul Durrant wrote:
> @@ -143,6 +148,8 @@ int kvm_xen_hypercall(struct kvm_vcpu *vcpu);
> #include <asm/xen/interface.h>
> #include <xen/interface/vcpu.h>
>
> +#define XEN_SIGNATURE "XenVMMXenVMM"
arch/x86/include/asm/xen/hypervisor.h also open codes the signature. Rather than
add a KVM-specific define, what about putting in xen/cpuid.h? (I've had a version
of this series sitting in my todo pile for far too long, sorry).
--
From: Sean Christopherson <seanjc@google.com>
Date: Mon, 11 Jul 2022 15:18:42 -0700
Subject: [PATCH] xen: Add a #define to provide Xen's CPUID signature as a
string
Add XEN_SIGNATURE instead of open coding it in xen_cpuid_base() so
that KVM can reuse the definition when querying a VM's CPUID.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
arch/x86/include/asm/xen/cpuid.h | 1 +
arch/x86/include/asm/xen/hypervisor.h | 3 ++-
2 files changed, 3 insertions(+), 1 deletion(-)
diff --git a/arch/x86/include/asm/xen/cpuid.h b/arch/x86/include/asm/xen/cpuid.h
index 6daa9b0c8d11..38f1bd153f42 100644
--- a/arch/x86/include/asm/xen/cpuid.h
+++ b/arch/x86/include/asm/xen/cpuid.h
@@ -49,6 +49,7 @@
* EBX-EDX: "XenVMMXenVMM" signature, allowing positive identification
* of a Xen host.
*/
+#define XEN_SIGNATURE "XenVMMXenVMM"
#define XEN_CPUID_SIGNATURE_EBX 0x566e6558 /* "XenV" */
#define XEN_CPUID_SIGNATURE_ECX 0x65584d4d /* "MMXe" */
#define XEN_CPUID_SIGNATURE_EDX 0x4d4d566e /* "nVMM" */
diff --git a/arch/x86/include/asm/xen/hypervisor.h b/arch/x86/include/asm/xen/hypervisor.h
index 16f548a661cf..32ff6583b3d9 100644
--- a/arch/x86/include/asm/xen/hypervisor.h
+++ b/arch/x86/include/asm/xen/hypervisor.h
@@ -37,10 +37,11 @@ extern struct shared_info *HYPERVISOR_shared_info;
extern struct start_info *xen_start_info;
#include <asm/processor.h>
+#include <asm/xen/cpuid.h>
static inline uint32_t xen_cpuid_base(void)
{
- return hypervisor_cpuid_base("XenVMMXenVMM", 2);
+ return hypervisor_cpuid_base(XEN_SIGNATURE, 2);
}
struct pci_dev;
base-commit: 91dc252b0dbb6879e4067f614df1e397fec532a1
--
On Wed, 2023-01-04 at 19:40 +0000, Sean Christopherson wrote: > > arch/x86/include/asm/xen/hypervisor.h also open codes the signature. Rather than > add a KVM-specific define, what about putting in xen/cpuid.h? (I've had a version > of this series sitting in my todo pile for far too long, sorry). xen/cpuid.h is an external header imported from Xen itself so in general I'd prefer to avoid modifying it unless we also send the changes upstream.
On Wed, Jan 04, 2023, David Woodhouse wrote: > On Wed, 2023-01-04 at 19:40 +0000, Sean Christopherson wrote: > > > > arch/x86/include/asm/xen/hypervisor.h also open codes the signature. Rather than > > add a KVM-specific define, what about putting in xen/cpuid.h? (I've had a version > > of this series sitting in my todo pile for far too long, sorry). > > xen/cpuid.h is an external header imported from Xen itself so in > general I'd prefer to avoid modifying it unless we also send the > changes upstream. *sigh* Fool me once... Can we shove it into arch/x86/include/asm/xen/hypervisor.h? Or is including that in KVM too confusing/ugly?
On 4 January 2023 20:20:55 GMT, Sean Christopherson <seanjc@google.com> wrote: >On Wed, Jan 04, 2023, David Woodhouse wrote: >> On Wed, 2023-01-04 at 19:40 +0000, Sean Christopherson wrote: >> > >> > arch/x86/include/asm/xen/hypervisor.h also open codes the signature. Rather than >> > add a KVM-specific define, what about putting in xen/cpuid.h? (I've had a version >> > of this series sitting in my todo pile for far too long, sorry). >> >> xen/cpuid.h is an external header imported from Xen itself so in >> general I'd prefer to avoid modifying it unless we also send the >> changes upstream. > >*sigh* Fool me once... > >Can we shove it into arch/x86/include/asm/xen/hypervisor.h? Or is including >that in KVM too confusing/ugly? Maybe, if that's our own header. We do include a bunch of stuff intended for use by Xen guests, in arch/x86/kvm/xen.c to provide Xen support. It's only the 32-bit compat bits we define for ourselves within arch/x86/kvm/xen.h.
On Tue, 2022-12-20 at 13:40 +0000, Paul Durrant wrote:
> 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>
Reviewed-by: David Woodhouse <dwmw@amazon.co.uk>
> ---
> 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: "H. Peter Anvin" <hpa@zytor.com>
> Cc: David Woodhouse <dwmw2@infradead.org>
>
> 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 | 11 ++++++-----
> arch/x86/kvm/cpuid.c | 2 ++
> arch/x86/kvm/x86.c | 1 +
> arch/x86/kvm/xen.c | 26 ++++++++++++++++++++++++++
> arch/x86/kvm/xen.h | 7 +++++++
> 5 files changed, 42 insertions(+), 5 deletions(-)
>
> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> index ff201ad35551..44329594bdf7 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;
> @@ -698,6 +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 {
> @@ -710,11 +716,6 @@ struct kvm_queued_exception {
> bool has_payload;
> };
>
> -struct kvm_hypervisor_cpuid {
> - u32 base;
> - u32 limit;
> -};
> -
> struct kvm_vcpu_arch {
> /*
> * rip and regs accesses must go through
> diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
> index 2468720f8d84..e661413ddf8d 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
> @@ -441,6 +442,7 @@ static int kvm_set_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid_entry2 *e2,
> vcpu->arch.cpuid_nent = nent;
>
> kvm_update_hypervisor_cpuid(vcpu, KVM_SIGNATURE, &vcpu->arch.kvm_cpuid);
> + kvm_update_hypervisor_cpuid(vcpu, XEN_SIGNATURE, &vcpu->arch.xen.cpuid);
> kvm_vcpu_after_set_cpuid(vcpu);
>
> return 0;
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index fd6c01a39312..60acc55f0c00 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 d7af40240248..46297521791c 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);
> @@ -2061,6 +2064,29 @@ 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..88dd085e10f8 100644
> --- a/arch/x86/kvm/xen.h
> +++ b/arch/x86/kvm/xen.h
> @@ -32,6 +32,7 @@ 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 +136,10 @@ 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);
> @@ -143,6 +148,8 @@ int kvm_xen_hypercall(struct kvm_vcpu *vcpu);
> #include <asm/xen/interface.h>
> #include <xen/interface/vcpu.h>
>
> +#define XEN_SIGNATURE "XenVMMXenVMM"
> +
> void kvm_xen_update_runstate(struct kvm_vcpu *vcpu, int state);
>
> static inline void kvm_xen_runstate_set_running(struct kvm_vcpu *vcpu)
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