On Wed, Sep 27, 2023, Phil Dennis-Jordan wrote:
> On Tue, Sep 26, 2023 at 6:08 PM Sean Christopherson <seanjc@xxxxxxxxxx> wrote:
> > The attached half-baked patch adds everything except the base "is this KVM?"
> > check and has only been compile tested on x86, feel free to use it as a starting
> > point (I wanted to get the basic gist compiling to make sure I wasn't leading you
> > completely astray)
>
> The attachment doesn't seem to have made it, would you mind trying
> again? Then I'll put together a v2 of the patch based on that.
Gah, sorry. This is why I usually inline patches, I forget to actually attach
the darn things 50% of the time.
>From 50e38e262149f8277110f4c965184463bbb7960b Mon Sep 17 00:00:00 2001
From: Sean Christopherson <seanjc@xxxxxxxxxx>
Date: Tue, 26 Sep 2023 09:04:35 -0700
Subject: [PATCH] tmp
---
lib/asm-generic/kvm_para.h | 4 +
lib/linux/kvm_para.h | 39 ++++++++++
lib/x86/asm/kvm_para.h | 153 +++++++++++++++++++++++++++++++++++++
lib/x86/processor.h | 4 +
x86/apic.c | 2 +-
5 files changed, 201 insertions(+), 1 deletion(-)
create mode 100644 lib/asm-generic/kvm_para.h
create mode 100644 lib/linux/kvm_para.h
create mode 100644 lib/x86/asm/kvm_para.h
diff --git a/lib/asm-generic/kvm_para.h b/lib/asm-generic/kvm_para.h
new file mode 100644
index 00000000..486f0af7
--- /dev/null
+++ b/lib/asm-generic/kvm_para.h
@@ -0,0 +1,4 @@
+/*
+ * There isn't anything here, but the file must not be empty or patch
+ * will delete it.
+ */
diff --git a/lib/linux/kvm_para.h b/lib/linux/kvm_para.h
new file mode 100644
index 00000000..960c7e93
--- /dev/null
+++ b/lib/linux/kvm_para.h
@@ -0,0 +1,39 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+#ifndef _UAPI__LINUX_KVM_PARA_H
+#define _UAPI__LINUX_KVM_PARA_H
+
+/*
+ * This header file provides a method for making a hypercall to the host
+ * Architectures should define:
+ * - kvm_hypercall0, kvm_hypercall1...
+ * - kvm_arch_para_features
+ * - kvm_para_available
+ */
+
+/* Return values for hypercalls */
+#define KVM_ENOSYS 1000
+#define KVM_EFAULT EFAULT
+#define KVM_EINVAL EINVAL
+#define KVM_E2BIG E2BIG
+#define KVM_EPERM EPERM
+#define KVM_EOPNOTSUPP 95
+
+#define KVM_HC_VAPIC_POLL_IRQ 1
+#define KVM_HC_MMU_OP 2
+#define KVM_HC_FEATURES 3
+#define KVM_HC_PPC_MAP_MAGIC_PAGE 4
+#define KVM_HC_KICK_CPU 5
+#define KVM_HC_MIPS_GET_CLOCK_FREQ 6
+#define KVM_HC_MIPS_EXIT_VM 7
+#define KVM_HC_MIPS_CONSOLE_OUTPUT 8
+#define KVM_HC_CLOCK_PAIRING 9
+#define KVM_HC_SEND_IPI 10
+#define KVM_HC_SCHED_YIELD 11
+#define KVM_HC_MAP_GPA_RANGE 12
+
+/*
+ * hypercalls use architecture specific
+ */
+#include <asm/kvm_para.h>
+
+#endif /* _UAPI__LINUX_KVM_PARA_H */
diff --git a/lib/x86/asm/kvm_para.h b/lib/x86/asm/kvm_para.h
new file mode 100644
index 00000000..6e64b27b
--- /dev/null
+++ b/lib/x86/asm/kvm_para.h
@@ -0,0 +1,153 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+#ifndef _UAPI_ASM_X86_KVM_PARA_H
+#define _UAPI_ASM_X86_KVM_PARA_H
+
+#include <linux/types.h>
+
+/* This CPUID returns the signature 'KVMKVMKVM' in ebx, ecx, and edx. It
+ * should be used to determine that a VM is running under KVM.
+ */
+#define KVM_CPUID_SIGNATURE 0x40000000
+#define KVM_SIGNATURE "KVMKVMKVM\0\0\0"
+
+/* This CPUID returns two feature bitmaps in eax, edx. Before enabling
+ * a particular paravirtualization, the appropriate feature bit should
+ * be checked in eax. The performance hint feature bit should be checked
+ * in edx.
+ */
+#define KVM_CPUID_FEATURES 0x40000001
+#define KVM_FEATURE_CLOCKSOURCE 0
+#define KVM_FEATURE_NOP_IO_DELAY 1
+#define KVM_FEATURE_MMU_OP 2
+/* This indicates that the new set of kvmclock msrs
+ * are available. The use of 0x11 and 0x12 is deprecated
+ */
+#define KVM_FEATURE_CLOCKSOURCE2 3
+#define KVM_FEATURE_ASYNC_PF 4
+#define KVM_FEATURE_STEAL_TIME 5
+#define KVM_FEATURE_PV_EOI 6
+#define KVM_FEATURE_PV_UNHALT 7
+#define KVM_FEATURE_PV_TLB_FLUSH 9
+#define KVM_FEATURE_ASYNC_PF_VMEXIT 10
+#define KVM_FEATURE_PV_SEND_IPI 11
+#define KVM_FEATURE_POLL_CONTROL 12
+#define KVM_FEATURE_PV_SCHED_YIELD 13
+#define KVM_FEATURE_ASYNC_PF_INT 14
+#define KVM_FEATURE_MSI_EXT_DEST_ID 15
+#define KVM_FEATURE_HC_MAP_GPA_RANGE 16
+#define KVM_FEATURE_MIGRATION_CONTROL 17
+
+#define KVM_HINTS_REALTIME 0
+
+/* The last 8 bits are used to indicate how to interpret the flags field
+ * in pvclock structure. If no bits are set, all flags are ignored.
+ */
+#define KVM_FEATURE_CLOCKSOURCE_STABLE_BIT 24
+
+#define MSR_KVM_WALL_CLOCK 0x11
+#define MSR_KVM_SYSTEM_TIME 0x12
+
+#define KVM_MSR_ENABLED 1
+/* Custom MSRs falls in the range 0x4b564d00-0x4b564dff */
+#define MSR_KVM_WALL_CLOCK_NEW 0x4b564d00
+#define MSR_KVM_SYSTEM_TIME_NEW 0x4b564d01
+#define MSR_KVM_ASYNC_PF_EN 0x4b564d02
+#define MSR_KVM_STEAL_TIME 0x4b564d03
+#define MSR_KVM_PV_EOI_EN 0x4b564d04
+#define MSR_KVM_POLL_CONTROL 0x4b564d05
+#define MSR_KVM_ASYNC_PF_INT 0x4b564d06
+#define MSR_KVM_ASYNC_PF_ACK 0x4b564d07
+#define MSR_KVM_MIGRATION_CONTROL 0x4b564d08
+
+struct kvm_steal_time {
+ __u64 steal;
+ __u32 version;
+ __u32 flags;
+ __u8 preempted;
+ __u8 u8_pad[3];
+ __u32 pad[11];
+};
+
+#define KVM_VCPU_PREEMPTED (1 << 0)
+#define KVM_VCPU_FLUSH_TLB (1 << 1)
+
+#define KVM_CLOCK_PAIRING_WALLCLOCK 0
+struct kvm_clock_pairing {
+ __s64 sec;
+ __s64 nsec;
+ __u64 tsc;
+ __u32 flags;
+ __u32 pad[9];
+};
+
+#define KVM_STEAL_ALIGNMENT_BITS 5
+#define KVM_STEAL_VALID_BITS ((-1ULL << (KVM_STEAL_ALIGNMENT_BITS + 1)))
+#define KVM_STEAL_RESERVED_MASK (((1 << KVM_STEAL_ALIGNMENT_BITS) - 1 ) << 1)
+
+#define KVM_MAX_MMU_OP_BATCH 32
+
+#define KVM_ASYNC_PF_ENABLED (1 << 0)
+#define KVM_ASYNC_PF_SEND_ALWAYS (1 << 1)
+#define KVM_ASYNC_PF_DELIVERY_AS_PF_VMEXIT (1 << 2)
+#define KVM_ASYNC_PF_DELIVERY_AS_INT (1 << 3)
+
+/* MSR_KVM_ASYNC_PF_INT */
+#define KVM_ASYNC_PF_VEC_MASK GENMASK(7, 0)
+
+/* MSR_KVM_MIGRATION_CONTROL */
+#define KVM_MIGRATION_READY (1 << 0)
+
+/* KVM_HC_MAP_GPA_RANGE */
+#define KVM_MAP_GPA_RANGE_PAGE_SZ_4K 0
+#define KVM_MAP_GPA_RANGE_PAGE_SZ_2M (1 << 0)
+#define KVM_MAP_GPA_RANGE_PAGE_SZ_1G (1 << 1)
+#define KVM_MAP_GPA_RANGE_ENC_STAT(n) (n << 4)
+#define KVM_MAP_GPA_RANGE_ENCRYPTED KVM_MAP_GPA_RANGE_ENC_STAT(1)
+#define KVM_MAP_GPA_RANGE_DECRYPTED KVM_MAP_GPA_RANGE_ENC_STAT(0)
+
+/* Operations for KVM_HC_MMU_OP */
+#define KVM_MMU_OP_WRITE_PTE 1
+#define KVM_MMU_OP_FLUSH_TLB 2
+#define KVM_MMU_OP_RELEASE_PT 3
+
+/* Payload for KVM_HC_MMU_OP */
+struct kvm_mmu_op_header {
+ __u32 op;
+ __u32 pad;
+};
+
+struct kvm_mmu_op_write_pte {
+ struct kvm_mmu_op_header header;
+ __u64 pte_phys;
+ __u64 pte_val;
+};
+
+struct kvm_mmu_op_flush_tlb {
+ struct kvm_mmu_op_header header;
+};
+
+struct kvm_mmu_op_release_pt {
+ struct kvm_mmu_op_header header;
+ __u64 pt_phys;
+};
+
+#define KVM_PV_REASON_PAGE_NOT_PRESENT 1
+#define KVM_PV_REASON_PAGE_READY 2
+
+struct kvm_vcpu_pv_apf_data {
+ /* Used for 'page not present' events delivered via #PF */
+ __u32 flags;
+
+ /* Used for 'page ready' events delivered via interrupt notification */
+ __u32 token;
+
+ __u8 pad[56];
+ __u32 enabled;
+};
+
+#define KVM_PV_EOI_BIT 0
+#define KVM_PV_EOI_MASK (0x1 << KVM_PV_EOI_BIT)
+#define KVM_PV_EOI_ENABLED KVM_PV_EOI_MASK
+#define KVM_PV_EOI_DISABLED 0x0
+
+#endif /* _UAPI_ASM_X86_KVM_PARA_H */
diff --git a/lib/x86/processor.h b/lib/x86/processor.h
index 44f4fd1e..7a7048f9 100644
--- a/lib/x86/processor.h
+++ b/lib/x86/processor.h
@@ -7,6 +7,8 @@
#include <bitops.h>
#include <stdint.h>
+#include <linux/kvm_para.h>
+
#define NONCANONICAL 0xaaaaaaaaaaaaaaaaull
#ifdef __x86_64__
@@ -284,6 +286,8 @@ static inline bool is_intel(void)
#define X86_FEATURE_VNMI (CPUID(0x8000000A, 0, EDX, 25))
#define X86_FEATURE_AMD_PMU_V2 (CPUID(0x80000022, 0, EAX, 0))
+#define X86_FEATURE_KVM_PV_SEND_IPI (CPUID(KVM_CPUID_FEATURES, 0, EAX, KVM_FEATURE_PV_SEND_IPI))
+
static inline bool this_cpu_has(u64 feature)
{
u32 input_eax = feature >> 32;
diff --git a/x86/apic.c b/x86/apic.c
index dd7e7834..61334543 100644
--- a/x86/apic.c
+++ b/x86/apic.c
@@ -658,7 +658,7 @@ static void test_pv_ipi(void)
int ret;
unsigned long a0 = 0xFFFFFFFF, a1 = 0, a2 = 0xFFFFFFFF, a3 = 0x0;
- if (!test_device_enabled())
+ if (!this_cpu_has(X86_FEATURE_KVM_PV_SEND_IPI))
return;
asm volatile("vmcall" : "=a"(ret) :"a"(KVM_HC_SEND_IPI), "b"(a0), "c"(a1), "d"(a2), "S"(a3));
base-commit: 038ae991814a8baf220ab2000fa2268d319213ae
--
2.42.0.582.g8ccd20d70d-goog
