If userspace knows that the kernel part supports 1GB pages it can enable
the corresponding cpuid bit so that guests actually use GB pages.
Signed-off-by: Joerg Roedel <joerg.roedel@xxxxxxx>
---
arch/x86/include/asm/kvm_host.h | 2 ++
arch/x86/kvm/svm.c | 6 ++++++
arch/x86/kvm/vmx.c | 6 ++++++
arch/x86/kvm/x86.c | 3 ++-
4 files changed, 16 insertions(+), 1 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index be2315b..f1f9149 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -528,6 +528,8 @@ struct kvm_x86_ops {
int (*set_tss_addr)(struct kvm *kvm, unsigned int addr);
int (*get_tdp_level)(void);
u64 (*get_mt_mask)(struct kvm_vcpu *vcpu, gfn_t gfn, bool is_mmio);
+ bool (*gb_page_enable)(void);
+
const struct trace_print_flags *exit_reasons_str;
};
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index fc14bdf..b0fc342 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -2755,6 +2755,11 @@ static const struct trace_print_flags svm_exit_reasons_str[] = {
{ -1, NULL }
};
+static bool svm_gb_page_enable(void)
+{
+ return npt_enabled;
+}
+
static struct kvm_x86_ops svm_x86_ops = {
.cpu_has_kvm_support = has_svm,
.disabled_by_bios = is_disabled,
@@ -2818,6 +2823,7 @@ static struct kvm_x86_ops svm_x86_ops = {
.get_mt_mask = svm_get_mt_mask,
.exit_reasons_str = svm_exit_reasons_str,
+ .gb_page_enable = svm_gb_page_enable,
};
static int __init svm_init(void)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 3a75db3..02529fb 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -3903,6 +3903,11 @@ static const struct trace_print_flags vmx_exit_reasons_str[] = {
{ -1, NULL }
};
+static bool vmx_gb_page_enable(void)
+{
+ return false;
+}
+
static struct kvm_x86_ops vmx_x86_ops = {
.cpu_has_kvm_support = cpu_has_kvm_support,
.disabled_by_bios = vmx_disabled_by_bios,
@@ -3964,6 +3969,7 @@ static struct kvm_x86_ops vmx_x86_ops = {
.get_mt_mask = vmx_get_mt_mask,
.exit_reasons_str = vmx_exit_reasons_str,
+ .gb_page_enable = vmx_gb_page_enable,
};
static int __init vmx_init(void)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 95fa45c..ae9017b 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1450,6 +1450,7 @@ static void do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
u32 index, int *nent, int maxnent)
{
unsigned f_nx = is_efer_nx() ? F(NX) : 0;
+ unsigned f_gbpages = kvm_x86_ops->gb_page_enable() ? F(GBPAGES) : 0;
#ifdef CONFIG_X86_64
unsigned f_lm = F(LM);
#else
@@ -1474,7 +1475,7 @@ static void do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
F(MTRR) | F(PGE) | F(MCA) | F(CMOV) |
F(PAT) | F(PSE36) | 0 /* Reserved */ |
f_nx | 0 /* Reserved */ | F(MMXEXT) | F(MMX) |
- F(FXSR) | F(FXSR_OPT) | 0 /* GBPAGES */ | 0 /* RDTSCP */ |
+ F(FXSR) | F(FXSR_OPT) | f_gbpages | 0 /* RDTSCP */ |
0 /* Reserved */ | f_lm | F(3DNOWEXT) | F(3DNOW);
/* cpuid 1.ecx */
const u32 kvm_supported_word4_x86_features =
--
1.6.3.3
--
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