From: Joerg Roedel <jroedel@xxxxxxx>
Replace the get_ghcb_msr_bits() function with macros and open code the
GHCB MSR setters with hypercall specific helper macros and functions.
This will avoid preserving any previous bits in the GHCB-MSR and
improves code readability.
Also get rid of the set_ghcb_msr() function and open-code it at its
call-sites for better code readability.
Suggested-by: Sean Christopherson <seanjc@xxxxxxxxxx>
Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
Reviewed-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
arch/x86/include/asm/sev-common.h | 9 +++++
arch/x86/kvm/svm/sev.c | 55 +++++++++++--------------------
2 files changed, 28 insertions(+), 36 deletions(-)
diff --git a/arch/x86/include/asm/sev-common.h b/arch/x86/include/asm/sev-common.h
index 1b2fd32b42fe..d49ebec1252a 100644
--- a/arch/x86/include/asm/sev-common.h
+++ b/arch/x86/include/asm/sev-common.h
@@ -53,6 +53,11 @@
/* GHCBData[63:32] */ \
(((unsigned long)fn) << 32))
+#define GHCB_MSR_CPUID_FN(msr) \
+ (((msr) >> GHCB_MSR_CPUID_FUNC_POS) & GHCB_MSR_CPUID_FUNC_MASK)
+#define GHCB_MSR_CPUID_REG(msr) \
+ (((msr) >> GHCB_MSR_CPUID_REG_POS) & GHCB_MSR_CPUID_REG_MASK)
+
/* AP Reset Hold */
#define GHCB_MSR_AP_RESET_HOLD_REQ 0x006
#define GHCB_MSR_AP_RESET_HOLD_RESP 0x007
@@ -72,6 +77,10 @@
(((((u64)reason_set) & 0xf) << 12) | \
/* GHCBData[23:16] */ \
((((u64)reason_val) & 0xff) << 16))
+#define GHCB_MSR_TERM_REASON_SET(msr) \
+ (((msr) >> GHCB_MSR_TERM_REASON_SET_POS) & GHCB_MSR_TERM_REASON_SET_MASK)
+#define GHCB_MSR_TERM_REASON(msr) \
+ (((msr) >> GHCB_MSR_TERM_REASON_POS) & GHCB_MSR_TERM_REASON_MASK)
#define GHCB_SEV_ES_GEN_REQ 0
#define GHCB_SEV_ES_PROT_UNSUPPORTED 1
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 6a22798eaaee..7632fc463458 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -2625,21 +2625,15 @@ static bool setup_vmgexit_scratch(struct vcpu_svm *svm, bool sync, u64 len)
return false;
}
-static void set_ghcb_msr_bits(struct vcpu_svm *svm, u64 value, u64 mask,
- unsigned int pos)
+static u64 ghcb_msr_cpuid_resp(u64 reg, u64 value)
{
- svm->vmcb->control.ghcb_gpa &= ~(mask << pos);
- svm->vmcb->control.ghcb_gpa |= (value & mask) << pos;
-}
+ u64 msr;
-static u64 get_ghcb_msr_bits(struct vcpu_svm *svm, u64 mask, unsigned int pos)
-{
- return (svm->vmcb->control.ghcb_gpa >> pos) & mask;
-}
+ msr = GHCB_MSR_CPUID_RESP;
+ msr |= (reg & GHCB_MSR_CPUID_REG_MASK) << GHCB_MSR_CPUID_REG_POS;
+ msr |= (value & GHCB_MSR_CPUID_VALUE_MASK) << GHCB_MSR_CPUID_VALUE_POS;
-static void set_ghcb_msr(struct vcpu_svm *svm, u64 value)
-{
- svm->vmcb->control.ghcb_gpa = value;
+ return msr;
}
static int sev_handle_vmgexit_msr_protocol(struct vcpu_svm *svm)
@@ -2656,16 +2650,14 @@ static int sev_handle_vmgexit_msr_protocol(struct vcpu_svm *svm)
switch (ghcb_info) {
case GHCB_MSR_SEV_INFO_REQ:
- set_ghcb_msr(svm, GHCB_MSR_SEV_INFO(GHCB_VERSION_MAX,
- GHCB_VERSION_MIN,
- sev_enc_bit));
+ svm->vmcb->control.ghcb_gpa = GHCB_MSR_SEV_INFO(GHCB_VERSION_MAX,
+ GHCB_VERSION_MIN,
+ sev_enc_bit);
break;
case GHCB_MSR_CPUID_REQ: {
u64 cpuid_fn, cpuid_reg, cpuid_value;
- cpuid_fn = get_ghcb_msr_bits(svm,
- GHCB_MSR_CPUID_FUNC_MASK,
- GHCB_MSR_CPUID_FUNC_POS);
+ cpuid_fn = GHCB_MSR_CPUID_FN(control->ghcb_gpa);
/* Initialize the registers needed by the CPUID intercept */
vcpu->arch.regs[VCPU_REGS_RAX] = cpuid_fn;
@@ -2677,9 +2669,8 @@ static int sev_handle_vmgexit_msr_protocol(struct vcpu_svm *svm)
break;
}
- cpuid_reg = get_ghcb_msr_bits(svm,
- GHCB_MSR_CPUID_REG_MASK,
- GHCB_MSR_CPUID_REG_POS);
+ cpuid_reg = GHCB_MSR_CPUID_REG(control->ghcb_gpa);
+
if (cpuid_reg == 0)
cpuid_value = vcpu->arch.regs[VCPU_REGS_RAX];
else if (cpuid_reg == 1)
@@ -2689,24 +2680,16 @@ static int sev_handle_vmgexit_msr_protocol(struct vcpu_svm *svm)
else
cpuid_value = vcpu->arch.regs[VCPU_REGS_RDX];
- set_ghcb_msr_bits(svm, cpuid_value,
- GHCB_MSR_CPUID_VALUE_MASK,
- GHCB_MSR_CPUID_VALUE_POS);
+ svm->vmcb->control.ghcb_gpa = ghcb_msr_cpuid_resp(cpuid_reg, cpuid_value);
- set_ghcb_msr_bits(svm, GHCB_MSR_CPUID_RESP,
- GHCB_MSR_INFO_MASK,
- GHCB_MSR_INFO_POS);
break;
}
case GHCB_MSR_TERM_REQ: {
u64 reason_set, reason_code;
- reason_set = get_ghcb_msr_bits(svm,
- GHCB_MSR_TERM_REASON_SET_MASK,
- GHCB_MSR_TERM_REASON_SET_POS);
- reason_code = get_ghcb_msr_bits(svm,
- GHCB_MSR_TERM_REASON_MASK,
- GHCB_MSR_TERM_REASON_POS);
+ reason_set = GHCB_MSR_TERM_REASON_SET(control->ghcb_gpa);
+ reason_code = GHCB_MSR_TERM_REASON(control->ghcb_gpa);
+
pr_info("SEV-ES guest requested termination: %#llx:%#llx\n",
reason_set, reason_code);
@@ -2897,9 +2880,9 @@ void sev_es_vcpu_reset(struct vcpu_svm *svm)
* Set the GHCB MSR value as per the GHCB specification when emulating
* vCPU RESET for an SEV-ES guest.
*/
- set_ghcb_msr(svm, GHCB_MSR_SEV_INFO(GHCB_VERSION_MAX,
- GHCB_VERSION_MIN,
- sev_enc_bit));
+ svm->vmcb->control.ghcb_gpa = GHCB_MSR_SEV_INFO(GHCB_VERSION_MAX,
+ GHCB_VERSION_MIN,
+ sev_enc_bit);
}
void sev_es_prepare_guest_switch(struct vcpu_svm *svm, unsigned int cpu)
--
2.34.1
