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
arch/x86/include/asm/kvm_host.h | 8 +++++++-
arch/x86/kvm/cpuid.c | 17 ++++++++++-------
arch/x86/kvm/x86.c | 1 +
arch/x86/kvm/xen.c | 26 ++++++++++++++++++++++++++
arch/x86/kvm/xen.h | 7 +++++++
5 files changed, 51 insertions(+), 8 deletions(-)
---
Cc: Borislav Petkov <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: David Woodhouse <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Paolo Bonzini <[email protected]>
Cc: Sean Christopherson <[email protected]>
Cc: Thomas Gleixner <[email protected]>
--
2.20.1
A sunsequent 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 <[email protected]>
---
Cc: Sean Christopherson <[email protected]>
Cc: Paolo Bonzini <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: David Woodhouse <[email protected]>
v6:
- New in this version
---
arch/x86/include/asm/kvm_host.h | 7 ++++++-
arch/x86/kvm/cpuid.c | 15 ++++++++-------
2 files changed, 14 insertions(+), 8 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index f35f1ff4427b..ff201ad35551 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -710,6 +710,11 @@ 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
@@ -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 0b5bf013fcb8..2468720f8d84 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -180,12 +180,13 @@ 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 void kvm_update_hypervisor_cpuid(struct kvm_vcpu *vcpu, const char *hypervisor_signature,
+ struct kvm_hypervisor_cpuid *hypervisor_cpuid)
{
u32 function;
struct kvm_cpuid_entry2 *entry;
- vcpu->arch.kvm_cpuid_base = 0;
+ memset(hypervisor_cpuid, 0, sizeof(*hypervisor_cpuid));
for_each_possible_hypervisor_cpuid_base(function) {
entry = kvm_find_cpuid_entry(vcpu, function);
@@ -197,9 +198,9 @@ 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, hypervisor_signature, sizeof(signature))) {
+ hypervisor_cpuid->base = function;
+ hypervisor_cpuid->limit = entry->eax;
break;
}
}
@@ -209,7 +210,7 @@ static void kvm_update_kvm_cpuid_base(struct kvm_vcpu *vcpu)
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 +440,7 @@ 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);
+ kvm_update_hypervisor_cpuid(vcpu, KVM_SIGNATURE, &vcpu->arch.kvm_cpuid);
kvm_vcpu_after_set_cpuid(vcpu);
return 0;
--
2.20.1
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 <[email protected]>
---
Cc: Sean Christopherson <[email protected]>
Cc: Paolo Bonzini <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: David Woodhouse <[email protected]>
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)
--
2.20.1
On Tue, 2022-12-20 at 13:40 +0000, Paul Durrant wrote:
> A sunsequent 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 <[email protected]>
> ---
Reviewed-by: David Woodhouse <[email protected]>
> Cc: Sean Christopherson <[email protected]>
> Cc: Paolo Bonzini <[email protected]>
> Cc: Thomas Gleixner <[email protected]>
> Cc: Ingo Molnar <[email protected]>
> Cc: Borislav Petkov <[email protected]>
> Cc: Dave Hansen <[email protected]>
> Cc: David Woodhouse <[email protected]>
>
> v6:
> - New in this version
> ---
> arch/x86/include/asm/kvm_host.h | 7 ++++++-
> arch/x86/kvm/cpuid.c | 15 ++++++++-------
> 2 files changed, 14 insertions(+), 8 deletions(-)
>
> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> index f35f1ff4427b..ff201ad35551 100644
> --- a/arch/x86/include/asm/kvm_host.h
> +++ b/arch/x86/include/asm/kvm_host.h
> @@ -710,6 +710,11 @@ 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
> @@ -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 0b5bf013fcb8..2468720f8d84 100644
> --- a/arch/x86/kvm/cpuid.c
> +++ b/arch/x86/kvm/cpuid.c
> @@ -180,12 +180,13 @@ 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 void kvm_update_hypervisor_cpuid(struct kvm_vcpu *vcpu, const char *hypervisor_signature,
> + struct kvm_hypervisor_cpuid *hypervisor_cpuid)
> {
> u32 function;
> struct kvm_cpuid_entry2 *entry;
>
> - vcpu->arch.kvm_cpuid_base = 0;
> + memset(hypervisor_cpuid, 0, sizeof(*hypervisor_cpuid));
>
> for_each_possible_hypervisor_cpuid_base(function) {
> entry = kvm_find_cpuid_entry(vcpu, function);
> @@ -197,9 +198,9 @@ 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, hypervisor_signature, sizeof(signature))) {
> + hypervisor_cpuid->base = function;
> + hypervisor_cpuid->limit = entry->eax;
> break;
> }
> }
> @@ -209,7 +210,7 @@ static void kvm_update_kvm_cpuid_base(struct kvm_vcpu *vcpu)
> 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 +440,7 @@ 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);
> + kvm_update_hypervisor_cpuid(vcpu, KVM_SIGNATURE, &vcpu->arch.kvm_cpuid);
> kvm_vcpu_after_set_cpuid(vcpu);
>
> return 0;
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 <[email protected]>
Reviewed-by: David Woodhouse <[email protected]>
> ---
> Cc: Sean Christopherson <[email protected]>
> Cc: Paolo Bonzini <[email protected]>
> Cc: Thomas Gleixner <[email protected]>
> Cc: Ingo Molnar <[email protected]>
> Cc: Borislav Petkov <[email protected]>
> Cc: Dave Hansen <[email protected]>
> Cc: "H. Peter Anvin" <[email protected]>
> Cc: David Woodhouse <[email protected]>
>
> 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)
On 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 <[email protected]>
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 <[email protected]>
---
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 Tue, Dec 20, 2022, Paul Durrant wrote:
> A sunsequent 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 <[email protected]>
> ---
> Cc: Sean Christopherson <[email protected]>
> Cc: Paolo Bonzini <[email protected]>
> Cc: Thomas Gleixner <[email protected]>
> Cc: Ingo Molnar <[email protected]>
> Cc: Borislav Petkov <[email protected]>
> Cc: Dave Hansen <[email protected]>
> Cc: David Woodhouse <[email protected]>
>
> v6:
> - New in this version
> ---
> arch/x86/include/asm/kvm_host.h | 7 ++++++-
> arch/x86/kvm/cpuid.c | 15 ++++++++-------
> 2 files changed, 14 insertions(+), 8 deletions(-)
>
> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> index f35f1ff4427b..ff201ad35551 100644
> --- a/arch/x86/include/asm/kvm_host.h
> +++ b/arch/x86/include/asm/kvm_host.h
> @@ -710,6 +710,11 @@ struct kvm_queued_exception {
> bool has_payload;
> };
>
> +struct kvm_hypervisor_cpuid {
> + u32 base;
> + u32 limit;
> +};
Probably makes sense to place this above "struct kvm_vcpu_xen" right away to
avoid the (very minor) churn.
> struct kvm_vcpu_arch {
> /*
> * rip and regs accesses must go through
> @@ -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 0b5bf013fcb8..2468720f8d84 100644
> --- a/arch/x86/kvm/cpuid.c
> +++ b/arch/x86/kvm/cpuid.c
> @@ -180,12 +180,13 @@ 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 void kvm_update_hypervisor_cpuid(struct kvm_vcpu *vcpu, const char *hypervisor_signature,
Please wrap. The 80 char limit is a soft limit, but should still be honored unless
there's a good reason to run over.
I also vote to name the param "sig" to keep line lengths short.
> + struct kvm_hypervisor_cpuid *hypervisor_cpuid)
Since the struct is a 64-bit value, what about making this a pure getter that
returns a copy?
static struct kvm_hypervisor_cpuid kvm_get_hypervisor_cpuid(struct kvm_vcpu *vcpu,
const char *sig)
{
struct kvm_hypervisor_cpuid cpuid = {};
struct kvm_cpuid_entry2 *entry;
u32 function;
for_each_possible_hypervisor_cpuid_base(cpuid.base) {
entry = kvm_find_cpuid_entry(vcpu, function);
if (entry) {
u32 signature[3];
signature[0] = entry->ebx;
signature[1] = entry->ecx;
signature[2] = entry->edx;
if (!memcmp(signature, sig, sizeof(signature))) {
cpuid.base = function;
cpuid.limit = entry->eax;
break;
}
}
}
return cpuid;
}
vcpu->arch.kvm_cpuid = kvm_get_hypervisor_cpuid(vcpu, KVM_SIGNATURE);
vcpu->arch.xen.cpuid = kvm_get_hypervisor_cpuid(vcpu, XEN_SIGNATURE);
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 <[email protected]> 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 04/01/2023 19:34, Sean Christopherson wrote:
> On Tue, Dec 20, 2022, Paul Durrant wrote:
>> A sunsequent 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 <[email protected]>
>> ---
>> Cc: Sean Christopherson <[email protected]>
>> Cc: Paolo Bonzini <[email protected]>
>> Cc: Thomas Gleixner <[email protected]>
>> Cc: Ingo Molnar <[email protected]>
>> Cc: Borislav Petkov <[email protected]>
>> Cc: Dave Hansen <[email protected]>
>> Cc: David Woodhouse <[email protected]>
>>
>> v6:
>> - New in this version
>> ---
>> arch/x86/include/asm/kvm_host.h | 7 ++++++-
>> arch/x86/kvm/cpuid.c | 15 ++++++++-------
>> 2 files changed, 14 insertions(+), 8 deletions(-)
>>
>> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
>> index f35f1ff4427b..ff201ad35551 100644
>> --- a/arch/x86/include/asm/kvm_host.h
>> +++ b/arch/x86/include/asm/kvm_host.h
>> @@ -710,6 +710,11 @@ struct kvm_queued_exception {
>> bool has_payload;
>> };
>>
>> +struct kvm_hypervisor_cpuid {
>> + u32 base;
>> + u32 limit;
>> +};
>
> Probably makes sense to place this above "struct kvm_vcpu_xen" right away to
> avoid the (very minor) churn.
>
Sure.
>> struct kvm_vcpu_arch {
>> /*
>> * rip and regs accesses must go through
>> @@ -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 0b5bf013fcb8..2468720f8d84 100644
>> --- a/arch/x86/kvm/cpuid.c
>> +++ b/arch/x86/kvm/cpuid.c
>> @@ -180,12 +180,13 @@ 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 void kvm_update_hypervisor_cpuid(struct kvm_vcpu *vcpu, const char *hypervisor_signature,
>
> Please wrap. The 80 char limit is a soft limit, but should still be honored unless
> there's a good reason to run over.
Ok.
>
> I also vote to name the param "sig" to keep line lengths short.
>
>> + struct kvm_hypervisor_cpuid *hypervisor_cpuid)
>
> Since the struct is a 64-bit value, what about making this a pure getter that
> returns a copy?
>
> static struct kvm_hypervisor_cpuid kvm_get_hypervisor_cpuid(struct kvm_vcpu *vcpu,
> const char *sig)
> {
> struct kvm_hypervisor_cpuid cpuid = {};
> struct kvm_cpuid_entry2 *entry;
> u32 function;
>
> for_each_possible_hypervisor_cpuid_base(cpuid.base) {
> entry = kvm_find_cpuid_entry(vcpu, function);
>
> if (entry) {
> u32 signature[3];
>
> signature[0] = entry->ebx;
> signature[1] = entry->ecx;
> signature[2] = entry->edx;
>
> if (!memcmp(signature, sig, sizeof(signature))) {
> cpuid.base = function;
> cpuid.limit = entry->eax;
> break;
> }
> }
> }
>
> return cpuid;
> }
>
>
> vcpu->arch.kvm_cpuid = kvm_get_hypervisor_cpuid(vcpu, KVM_SIGNATURE);
> vcpu->arch.xen.cpuid = kvm_get_hypervisor_cpuid(vcpu, XEN_SIGNATURE);
Yes, if that's preferable then no problem.
Paul
On Thu, Jan 05, 2023, Paul Durrant wrote:
> On 04/01/2023 19:34, Sean Christopherson wrote:
> > Since the struct is a 64-bit value, what about making this a pure getter that
> > returns a copy?
> >
> > static struct kvm_hypervisor_cpuid kvm_get_hypervisor_cpuid(struct kvm_vcpu *vcpu,
> > const char *sig)
> > {
> > struct kvm_hypervisor_cpuid cpuid = {};
> > struct kvm_cpuid_entry2 *entry;
> > u32 function;
> >
> > for_each_possible_hypervisor_cpuid_base(cpuid.base) {
> > entry = kvm_find_cpuid_entry(vcpu, function);
> >
> > if (entry) {
> > u32 signature[3];
> >
> > signature[0] = entry->ebx;
> > signature[1] = entry->ecx;
> > signature[2] = entry->edx;
> >
> > if (!memcmp(signature, sig, sizeof(signature))) {
> > cpuid.base = function;
> > cpuid.limit = entry->eax;
> > break;
> > }
> > }
> > }
> >
> > return cpuid;
> > }
> >
> >
> > vcpu->arch.kvm_cpuid = kvm_get_hypervisor_cpuid(vcpu, KVM_SIGNATURE);
> > vcpu->arch.xen.cpuid = kvm_get_hypervisor_cpuid(vcpu, XEN_SIGNATURE);
>
> Yes, if that's preferable then no problem.
I like it (obviously), but it's probably worth waiting a few days to see what
others think before posting a new version.
On 05/01/2023 18:09, Sean Christopherson wrote:
> On Thu, Jan 05, 2023, Paul Durrant wrote:
>> On 04/01/2023 19:34, Sean Christopherson wrote:
>>> Since the struct is a 64-bit value, what about making this a pure getter that
>>> returns a copy?
>>>
>>> static struct kvm_hypervisor_cpuid kvm_get_hypervisor_cpuid(struct kvm_vcpu *vcpu,
>>> const char *sig)
>>> {
>>> struct kvm_hypervisor_cpuid cpuid = {};
>>> struct kvm_cpuid_entry2 *entry;
>>> u32 function;
>>>
>>> for_each_possible_hypervisor_cpuid_base(cpuid.base) {
>>> entry = kvm_find_cpuid_entry(vcpu, function);
>>>
>>> if (entry) {
>>> u32 signature[3];
>>>
>>> signature[0] = entry->ebx;
>>> signature[1] = entry->ecx;
>>> signature[2] = entry->edx;
>>>
>>> if (!memcmp(signature, sig, sizeof(signature))) {
>>> cpuid.base = function;
>>> cpuid.limit = entry->eax;
>>> break;
>>> }
>>> }
>>> }
>>>
>>> return cpuid;
>>> }
>>>
>>>
>>> vcpu->arch.kvm_cpuid = kvm_get_hypervisor_cpuid(vcpu, KVM_SIGNATURE);
>>> vcpu->arch.xen.cpuid = kvm_get_hypervisor_cpuid(vcpu, XEN_SIGNATURE);
>>
>> Yes, if that's preferable then no problem.
>
> I like it (obviously), but it's probably worth waiting a few days to see what
> others think before posting a new version.
I think it's cleaner too, and I already did the typing so I may as well
post. I don't think anyone else has expressed any strong opinions on the
code either way.
Paul