[RFC PATCH 5/12] HV: Add ghcb hvcall support for SNP VM
STALE2039d
From: Tianyu Lan <hidden>
Date: 2021-02-28 15:08:08
Also in:
lkml
Subsystem:
hyper-v/azure core and drivers, the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
"K. Y. Srinivasan", Haiyang Zhang, Wei Liu, Dexuan Cui, Long Li, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
Revision rfc of 11 in this series.
Revisions (11)
From: Tianyu Lan <redacted> 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 <redacted> --- arch/x86/hyperv/ivm.c | 69 +++++++++++++++++++++++++++++++++ arch/x86/include/asm/mshyperv.h | 1 + drivers/hv/connection.c | 6 ++- drivers/hv/hv.c | 8 +++- 4 files changed, 82 insertions(+), 2 deletions(-)
diff --git a/arch/x86/hyperv/ivm.c b/arch/x86/hyperv/ivm.c
index 4332bf7aaf9b..feaabcd151f5 100644
--- a/arch/x86/hyperv/ivm.c
+++ b/arch/x86/hyperv/ivm.c@@ -14,8 +14,77 @@ 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); +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; + + 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; + } + + memset(hv_ghcb, 0x00, HV_HYP_PAGE_SIZE); + hv_ghcb->ghcb.protocol_version = 1; + hv_ghcb->ghcb.ghcb_usage = 1; + + 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 f624d72b99d3..c8f66d269e5b 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h@@ -274,6 +274,7 @@ 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 c83612cddb99..79bca653dce9 100644
--- a/drivers/hv/connection.c
+++ b/drivers/hv/connection.c@@ -442,6 +442,10 @@ 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 28e28ccc2081..6c64a7fd1ebd 100644
--- a/drivers/hv/hv.c
+++ b/drivers/hv/hv.c@@ -60,7 +60,13 @@ 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
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2.25.1