diff mbox series

[V3,06/13] HV: Add ghcb hvcall support for SNP VM

Message ID 20210809175620.720923-7-ltykernel@gmail.com (mailing list archive)
State Superseded
Headers show
Series x86/Hyper-V: Add Hyper-V Isolation VM support | expand

Commit Message

Tianyu Lan Aug. 9, 2021, 5:56 p.m. UTC 
From: Tianyu Lan <Tianyu.Lan@microsoft.com>

Hyper-V provides ghcb hvcall to handle VMBus
HVCALL_SIGNAL_EVENT and HVCALL_POST_MESSAGE
msg in SNP Isolation VM. Add such support.

Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
---
 arch/x86/hyperv/ivm.c           | 43 +++++++++++++++++++++++++++++++++
 arch/x86/include/asm/mshyperv.h |  1 +
 drivers/hv/connection.c         |  6 ++++-
 drivers/hv/hv.c                 |  8 +++++-
 include/asm-generic/mshyperv.h  | 29 ++++++++++++++++++++++
 5 files changed, 85 insertions(+), 2 deletions(-)

Comments

Michael Kelley (LINUX) Aug. 13, 2021, 8:42 p.m. UTC | #1 
From: Tianyu Lan <ltykernel@gmail.com> Sent: Monday, August 9, 2021 10:56 AM
> 
> Hyper-V provides ghcb hvcall to handle VMBus
> HVCALL_SIGNAL_EVENT and HVCALL_POST_MESSAGE
> msg in SNP Isolation VM. Add such support.
> 
> Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
> ---
>  arch/x86/hyperv/ivm.c           | 43 +++++++++++++++++++++++++++++++++
>  arch/x86/include/asm/mshyperv.h |  1 +
>  drivers/hv/connection.c         |  6 ++++-
>  drivers/hv/hv.c                 |  8 +++++-
>  include/asm-generic/mshyperv.h  | 29 ++++++++++++++++++++++
>  5 files changed, 85 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/x86/hyperv/ivm.c b/arch/x86/hyperv/ivm.c
> index ec0e5c259740..c13ec5560d73 100644
> --- a/arch/x86/hyperv/ivm.c
> +++ b/arch/x86/hyperv/ivm.c
> @@ -15,6 +15,49 @@
>  #include <asm/io.h>
>  #include <asm/mshyperv.h>
> 
> +#define GHCB_USAGE_HYPERV_CALL	1
> +
> +u64 hv_ghcb_hypercall(u64 control, void *input, void *output, u32 input_size)
> +{
> +	union hv_ghcb *hv_ghcb;
> +	void **ghcb_base;
> +	unsigned long flags;
> +
> +	if (!ms_hyperv.ghcb_base)
> +		return -EFAULT;
> +
> +	WARN_ON(in_nmi());
> +
> +	local_irq_save(flags);
> +	ghcb_base = (void **)this_cpu_ptr(ms_hyperv.ghcb_base);
> +	hv_ghcb = (union hv_ghcb *)*ghcb_base;
> +	if (!hv_ghcb) {
> +		local_irq_restore(flags);
> +		return -EFAULT;
> +	}
> +
> +	hv_ghcb->ghcb.protocol_version = GHCB_PROTOCOL_MAX;
> +	hv_ghcb->ghcb.ghcb_usage = GHCB_USAGE_HYPERV_CALL;
> +
> +	hv_ghcb->hypercall.outputgpa = (u64)output;
> +	hv_ghcb->hypercall.hypercallinput.asuint64 = 0;
> +	hv_ghcb->hypercall.hypercallinput.callcode = control;
> +
> +	if (input_size)
> +		memcpy(hv_ghcb->hypercall.hypercalldata, input, input_size);
> +
> +	VMGEXIT();
> +
> +	hv_ghcb->ghcb.ghcb_usage = 0xffffffff;
> +	memset(hv_ghcb->ghcb.save.valid_bitmap, 0,
> +	       sizeof(hv_ghcb->ghcb.save.valid_bitmap));
> +
> +	local_irq_restore(flags);
> +
> +	return hv_ghcb->hypercall.hypercalloutput.callstatus;
> +}
> +EXPORT_SYMBOL_GPL(hv_ghcb_hypercall);

This function is called from architecture independent code, so it needs a
default no-op stub to enable the code to compile on ARM64.  The stub should
always return failure.

> +
>  void hv_ghcb_msr_write(u64 msr, u64 value)
>  {
>  	union hv_ghcb *hv_ghcb;
> diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
> index 730985676ea3..a30c60f189a3 100644
> --- a/arch/x86/include/asm/mshyperv.h
> +++ b/arch/x86/include/asm/mshyperv.h
> @@ -255,6 +255,7 @@ void hv_sint_rdmsrl_ghcb(u64 msr, u64 *value);
>  void hv_signal_eom_ghcb(void);
>  void hv_ghcb_msr_write(u64 msr, u64 value);
>  void hv_ghcb_msr_read(u64 msr, u64 *value);
> +u64 hv_ghcb_hypercall(u64 control, void *input, void *output, u32 input_size);
> 
>  #define hv_get_synint_state_ghcb(int_num, val)			\
>  	hv_sint_rdmsrl_ghcb(HV_X64_MSR_SINT0 + int_num, val)
> diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
> index 5e479d54918c..6d315c1465e0 100644
> --- a/drivers/hv/connection.c
> +++ b/drivers/hv/connection.c
> @@ -447,6 +447,10 @@ void vmbus_set_event(struct vmbus_channel *channel)
> 
>  	++channel->sig_events;
> 
> -	hv_do_fast_hypercall8(HVCALL_SIGNAL_EVENT, channel->sig_event);
> +	if (hv_isolation_type_snp())
> +		hv_ghcb_hypercall(HVCALL_SIGNAL_EVENT, &channel->sig_event,
> +				NULL, sizeof(u64));
> +	else
> +		hv_do_fast_hypercall8(HVCALL_SIGNAL_EVENT, channel->sig_event);
>  }
>  EXPORT_SYMBOL_GPL(vmbus_set_event);
> diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
> index 59f7173c4d9f..e5c9fc467893 100644
> --- a/drivers/hv/hv.c
> +++ b/drivers/hv/hv.c
> @@ -98,7 +98,13 @@ int hv_post_message(union hv_connection_id connection_id,
>  	aligned_msg->payload_size = payload_size;
>  	memcpy((void *)aligned_msg->payload, payload, payload_size);
> 
> -	status = hv_do_hypercall(HVCALL_POST_MESSAGE, aligned_msg, NULL);
> +	if (hv_isolation_type_snp())
> +		status = hv_ghcb_hypercall(HVCALL_POST_MESSAGE,
> +				(void *)aligned_msg, NULL,
> +				sizeof(struct hv_input_post_message));
> +	else
> +		status = hv_do_hypercall(HVCALL_POST_MESSAGE,
> +				aligned_msg, NULL);
> 
>  	/* Preemption must remain disabled until after the hypercall
>  	 * so some other thread can't get scheduled onto this cpu and
> diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
> index 90dac369a2dc..400181b855c1 100644
> --- a/include/asm-generic/mshyperv.h
> +++ b/include/asm-generic/mshyperv.h
> @@ -31,6 +31,35 @@
> 
>  union hv_ghcb {
>  	struct ghcb ghcb;
> +	struct {
> +		u64 hypercalldata[509];
> +		u64 outputgpa;
> +		union {
> +			union {
> +				struct {
> +					u32 callcode        : 16;
> +					u32 isfast          : 1;
> +					u32 reserved1       : 14;
> +					u32 isnested        : 1;
> +					u32 countofelements : 12;
> +					u32 reserved2       : 4;
> +					u32 repstartindex   : 12;
> +					u32 reserved3       : 4;
> +				};
> +				u64 asuint64;
> +			} hypercallinput;
> +			union {
> +				struct {
> +					u16 callstatus;
> +					u16 reserved1;
> +					u32 elementsprocessed : 12;
> +					u32 reserved2         : 20;
> +				};
> +				u64 asunit64;
> +			} hypercalloutput;
> +		};
> +		u64 reserved2;
> +	} hypercall;
>  } __packed __aligned(PAGE_SIZE);

Alignment should be to HV_HYP_PAGE_SIZE.  And it would be a good safety
play to have a BUILD_BUG_ON() somewhere asserting that
sizeof(union hv_ghcb) == HV_HYP_PAGE_SIZE.

> 
>  struct ms_hyperv_info {
> --
> 2.25.1
diff mbox series

Patch

diff --git a/arch/x86/hyperv/ivm.c b/arch/x86/hyperv/ivm.c
index ec0e5c259740..c13ec5560d73 100644
--- a/arch/x86/hyperv/ivm.c
+++ b/arch/x86/hyperv/ivm.c
@@ -15,6 +15,49 @@ 
 #include <asm/io.h>
 #include <asm/mshyperv.h>
 
+#define GHCB_USAGE_HYPERV_CALL	1
+
+u64 hv_ghcb_hypercall(u64 control, void *input, void *output, u32 input_size)
+{
+	union hv_ghcb *hv_ghcb;
+	void **ghcb_base;
+	unsigned long flags;
+
+	if (!ms_hyperv.ghcb_base)
+		return -EFAULT;
+
+	WARN_ON(in_nmi());
+
+	local_irq_save(flags);
+	ghcb_base = (void **)this_cpu_ptr(ms_hyperv.ghcb_base);
+	hv_ghcb = (union hv_ghcb *)*ghcb_base;
+	if (!hv_ghcb) {
+		local_irq_restore(flags);
+		return -EFAULT;
+	}
+
+	hv_ghcb->ghcb.protocol_version = GHCB_PROTOCOL_MAX;
+	hv_ghcb->ghcb.ghcb_usage = GHCB_USAGE_HYPERV_CALL;
+
+	hv_ghcb->hypercall.outputgpa = (u64)output;
+	hv_ghcb->hypercall.hypercallinput.asuint64 = 0;
+	hv_ghcb->hypercall.hypercallinput.callcode = control;
+
+	if (input_size)
+		memcpy(hv_ghcb->hypercall.hypercalldata, input, input_size);
+
+	VMGEXIT();
+
+	hv_ghcb->ghcb.ghcb_usage = 0xffffffff;
+	memset(hv_ghcb->ghcb.save.valid_bitmap, 0,
+	       sizeof(hv_ghcb->ghcb.save.valid_bitmap));
+
+	local_irq_restore(flags);
+
+	return hv_ghcb->hypercall.hypercalloutput.callstatus;
+}
+EXPORT_SYMBOL_GPL(hv_ghcb_hypercall);
+
 void hv_ghcb_msr_write(u64 msr, u64 value)
 {
 	union hv_ghcb *hv_ghcb;
diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index 730985676ea3..a30c60f189a3 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -255,6 +255,7 @@  void hv_sint_rdmsrl_ghcb(u64 msr, u64 *value);
 void hv_signal_eom_ghcb(void);
 void hv_ghcb_msr_write(u64 msr, u64 value);
 void hv_ghcb_msr_read(u64 msr, u64 *value);
+u64 hv_ghcb_hypercall(u64 control, void *input, void *output, u32 input_size);
 
 #define hv_get_synint_state_ghcb(int_num, val)			\
 	hv_sint_rdmsrl_ghcb(HV_X64_MSR_SINT0 + int_num, val)
diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
index 5e479d54918c..6d315c1465e0 100644
--- a/drivers/hv/connection.c
+++ b/drivers/hv/connection.c
@@ -447,6 +447,10 @@  void vmbus_set_event(struct vmbus_channel *channel)
 
 	++channel->sig_events;
 
-	hv_do_fast_hypercall8(HVCALL_SIGNAL_EVENT, channel->sig_event);
+	if (hv_isolation_type_snp())
+		hv_ghcb_hypercall(HVCALL_SIGNAL_EVENT, &channel->sig_event,
+				NULL, sizeof(u64));
+	else
+		hv_do_fast_hypercall8(HVCALL_SIGNAL_EVENT, channel->sig_event);
 }
 EXPORT_SYMBOL_GPL(vmbus_set_event);
diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
index 59f7173c4d9f..e5c9fc467893 100644
--- a/drivers/hv/hv.c
+++ b/drivers/hv/hv.c
@@ -98,7 +98,13 @@  int hv_post_message(union hv_connection_id connection_id,
 	aligned_msg->payload_size = payload_size;
 	memcpy((void *)aligned_msg->payload, payload, payload_size);
 
-	status = hv_do_hypercall(HVCALL_POST_MESSAGE, aligned_msg, NULL);
+	if (hv_isolation_type_snp())
+		status = hv_ghcb_hypercall(HVCALL_POST_MESSAGE,
+				(void *)aligned_msg, NULL,
+				sizeof(struct hv_input_post_message));
+	else
+		status = hv_do_hypercall(HVCALL_POST_MESSAGE,
+				aligned_msg, NULL);
 
 	/* Preemption must remain disabled until after the hypercall
 	 * so some other thread can't get scheduled onto this cpu and
diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
index 90dac369a2dc..400181b855c1 100644
--- a/include/asm-generic/mshyperv.h
+++ b/include/asm-generic/mshyperv.h
@@ -31,6 +31,35 @@ 
 
 union hv_ghcb {
 	struct ghcb ghcb;
+	struct {
+		u64 hypercalldata[509];
+		u64 outputgpa;
+		union {
+			union {
+				struct {
+					u32 callcode        : 16;
+					u32 isfast          : 1;
+					u32 reserved1       : 14;
+					u32 isnested        : 1;
+					u32 countofelements : 12;
+					u32 reserved2       : 4;
+					u32 repstartindex   : 12;
+					u32 reserved3       : 4;
+				};
+				u64 asuint64;
+			} hypercallinput;
+			union {
+				struct {
+					u16 callstatus;
+					u16 reserved1;
+					u32 elementsprocessed : 12;
+					u32 reserved2         : 20;
+				};
+				u64 asunit64;
+			} hypercalloutput;
+		};
+		u64 reserved2;
+	} hypercall;
 } __packed __aligned(PAGE_SIZE);
 
 struct ms_hyperv_info {