Commit 55e6f8f2 authored by Paolo Bonzini's avatar Paolo Bonzini
Browse files

Merge tag 'kvm-x86-svm-6.12' of https://github.com/kvm-x86/linux into HEAD 

KVM SVM changes for 6.12:

 - Don't stuff the RSB after VM-Exit when RETPOLINE=y and AutoIBRS is enabled,
   i.e. when the CPU has already flushed the RSB.

 - Trace the per-CPU host save area as a VMCB pointer to improve readability
   and cleanup the retrieval of the SEV-ES host save area.

 - Remove unnecessary accounting of temporary nested VMCB related allocations.
parents 43d97b2e 4440337a

arch/x86/include/asm/svm.h

+15 −5
Original line number Diff line number Diff line
@@ -516,6 +516,20 @@ struct ghcb { 
	u32 ghcb_usage;

} __packed;



struct vmcb {

	struct vmcb_control_area control;

	union {

		struct vmcb_save_area save;



		/*

		 * For SEV-ES VMs, the save area in the VMCB is used only to

		 * save/load host state.  Guest state resides in a separate

		 * page, the aptly named VM Save Area (VMSA), that is encrypted

		 * with the guest's private key.

		 */

		struct sev_es_save_area host_sev_es_save;

	};

} __packed;



#define EXPECTED_VMCB_SAVE_AREA_SIZE		744

#define EXPECTED_GHCB_SAVE_AREA_SIZE		1032
@@ -532,6 +546,7 @@ static inline void __unused_size_checks(void) 
	BUILD_BUG_ON(sizeof(struct ghcb_save_area)	!= EXPECTED_GHCB_SAVE_AREA_SIZE);

	BUILD_BUG_ON(sizeof(struct sev_es_save_area)	!= EXPECTED_SEV_ES_SAVE_AREA_SIZE);

	BUILD_BUG_ON(sizeof(struct vmcb_control_area)	!= EXPECTED_VMCB_CONTROL_AREA_SIZE);

	BUILD_BUG_ON(offsetof(struct vmcb, save)	!= EXPECTED_VMCB_CONTROL_AREA_SIZE);

	BUILD_BUG_ON(sizeof(struct ghcb)		!= EXPECTED_GHCB_SIZE);



	/* Check offsets of reserved fields */
@@ -568,11 +583,6 @@ static inline void __unused_size_checks(void) 
	BUILD_BUG_RESERVED_OFFSET(ghcb, 0xff0);

}



struct vmcb {

	struct vmcb_control_area control;

	struct vmcb_save_area save;

} __packed;



#define SVM_CPUID_FUNC 0x8000000a



#define SVM_SELECTOR_S_SHIFT 4

arch/x86/kvm/svm/nested.c

+2 −2
Original line number Diff line number Diff line
@@ -1693,8 +1693,8 @@ static int svm_set_nested_state(struct kvm_vcpu *vcpu, 
		return -EINVAL;



	ret  = -ENOMEM;

	ctl  = kzalloc(sizeof(*ctl),  GFP_KERNEL_ACCOUNT);

	save = kzalloc(sizeof(*save), GFP_KERNEL_ACCOUNT);

	ctl  = kzalloc(sizeof(*ctl),  GFP_KERNEL);

	save = kzalloc(sizeof(*save), GFP_KERNEL);

	if (!ctl || !save)

		goto out_free;

arch/x86/kvm/svm/svm.c

+12 −12
Original line number Diff line number Diff line
@@ -573,7 +573,7 @@ static void __svm_write_tsc_multiplier(u64 multiplier) 


static __always_inline struct sev_es_save_area *sev_es_host_save_area(struct svm_cpu_data *sd)

{

	return page_address(sd->save_area) + 0x400;

	return &sd->save_area->host_sev_es_save;

}



static inline void kvm_cpu_svm_disable(void)
@@ -696,7 +696,7 @@ static void svm_cpu_uninit(int cpu) 
		return;



	kfree(sd->sev_vmcbs);

	__free_page(sd->save_area);

	__free_page(__sme_pa_to_page(sd->save_area_pa));

	sd->save_area_pa = 0;

	sd->save_area = NULL;

}
@@ -704,23 +704,24 @@ static void svm_cpu_uninit(int cpu) 
static int svm_cpu_init(int cpu)

{

	struct svm_cpu_data *sd = per_cpu_ptr(&svm_data, cpu);

	struct page *save_area_page;

	int ret = -ENOMEM;



	memset(sd, 0, sizeof(struct svm_cpu_data));

	sd->save_area = snp_safe_alloc_page_node(cpu_to_node(cpu), GFP_KERNEL);

	if (!sd->save_area)

	save_area_page = snp_safe_alloc_page_node(cpu_to_node(cpu), GFP_KERNEL);

	if (!save_area_page)

		return ret;



	ret = sev_cpu_init(sd);

	if (ret)

		goto free_save_area;



	sd->save_area_pa = __sme_page_pa(sd->save_area);

	sd->save_area = page_address(save_area_page);

	sd->save_area_pa = __sme_page_pa(save_area_page);

	return 0;



free_save_area:

	__free_page(sd->save_area);

	sd->save_area = NULL;

	__free_page(save_area_page);

	return ret;



}
@@ -1124,8 +1125,7 @@ static void svm_hardware_unsetup(void) 
	for_each_possible_cpu(cpu)

		svm_cpu_uninit(cpu);



	__free_pages(pfn_to_page(iopm_base >> PAGE_SHIFT),

	get_order(IOPM_SIZE));

	__free_pages(__sme_pa_to_page(iopm_base), get_order(IOPM_SIZE));

	iopm_base = 0;

}
@@ -1301,7 +1301,7 @@ static void init_vmcb(struct kvm_vcpu *vcpu) 
	if (!kvm_hlt_in_guest(vcpu->kvm))

		svm_set_intercept(svm, INTERCEPT_HLT);



	control->iopm_base_pa = __sme_set(iopm_base);

	control->iopm_base_pa = iopm_base;

	control->msrpm_base_pa = __sme_set(__pa(svm->msrpm));

	control->int_ctl = V_INTR_MASKING_MASK;
@@ -1503,7 +1503,7 @@ static void svm_vcpu_free(struct kvm_vcpu *vcpu) 


	sev_free_vcpu(vcpu);



	__free_page(pfn_to_page(__sme_clr(svm->vmcb01.pa) >> PAGE_SHIFT));

	__free_page(__sme_pa_to_page(svm->vmcb01.pa));

	__free_pages(virt_to_page(svm->msrpm), get_order(MSRPM_SIZE));

}
@@ -5281,7 +5281,7 @@ static __init int svm_hardware_setup(void) 


	iopm_va = page_address(iopm_pages);

	memset(iopm_va, 0xff, PAGE_SIZE * (1 << order));

	iopm_base = page_to_pfn(iopm_pages) << PAGE_SHIFT;

	iopm_base = __sme_page_pa(iopm_pages);



	init_msrpm_offsets();

arch/x86/kvm/svm/svm.h

+16 −2
Original line number Diff line number Diff line
@@ -25,7 +25,21 @@ 
#include "cpuid.h"

#include "kvm_cache_regs.h"



#define __sme_page_pa(x) __sme_set(page_to_pfn(x) << PAGE_SHIFT)

/*

 * Helpers to convert to/from physical addresses for pages whose address is

 * consumed directly by hardware.  Even though it's a physical address, SVM

 * often restricts the address to the natural width, hence 'unsigned long'

 * instead of 'hpa_t'.

 */

static inline unsigned long __sme_page_pa(struct page *page)

{

	return __sme_set(page_to_pfn(page) << PAGE_SHIFT);

}



static inline struct page *__sme_pa_to_page(unsigned long pa)

{

	return pfn_to_page(__sme_clr(pa) >> PAGE_SHIFT);

}



#define	IOPM_SIZE PAGE_SIZE * 3

#define	MSRPM_SIZE PAGE_SIZE * 2
@@ -321,7 +335,7 @@ struct svm_cpu_data { 
	u32 next_asid;

	u32 min_asid;



	struct page *save_area;

	struct vmcb *save_area;

	unsigned long save_area_pa;



	struct vmcb *current_vmcb;

arch/x86/kvm/svm/vmenter.S

+2 −6
Original line number Diff line number Diff line
@@ -209,10 +209,8 @@ SYM_FUNC_START(__svm_vcpu_run) 
7:	vmload %_ASM_AX

8:



#ifdef CONFIG_MITIGATION_RETPOLINE

	/* IMPORTANT: Stuff the RSB immediately after VM-Exit, before RET! */

	FILL_RETURN_BUFFER %_ASM_AX, RSB_CLEAR_LOOPS, X86_FEATURE_RETPOLINE

#endif

	FILL_RETURN_BUFFER %_ASM_AX, RSB_CLEAR_LOOPS, X86_FEATURE_RSB_VMEXIT



	/* Clobbers RAX, RCX, RDX.  */

	RESTORE_HOST_SPEC_CTRL
@@ -348,10 +346,8 @@ SYM_FUNC_START(__svm_sev_es_vcpu_run) 


2:	cli



#ifdef CONFIG_MITIGATION_RETPOLINE

	/* IMPORTANT: Stuff the RSB immediately after VM-Exit, before RET! */

	FILL_RETURN_BUFFER %rax, RSB_CLEAR_LOOPS, X86_FEATURE_RETPOLINE

#endif

	FILL_RETURN_BUFFER %rax, RSB_CLEAR_LOOPS, X86_FEATURE_RSB_VMEXIT



	/* Clobbers RAX, RCX, RDX, consumes RDI (@svm) and RSI (@spec_ctrl_intercepted). */

	RESTORE_HOST_SPEC_CTRL